Strong, yet split hydrogen bonding with ice rules in delafossite (H/D)RhO2
Data files
Apr 23, 2026 version files 39.11 MB
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2.5mmMAS_1H_HRhO2.txt
359.90 KB
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2.5mmMAS_1H_Rotor.txt
199.91 KB
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2.5mmMAS_2H_DRhO2.txt
191.32 KB
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DRhO2_0T_Cp.dat
89.56 KB
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DRhO2_298K_XRD-NPD.cif
1.85 KB
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DRhO2_DSC.txt
16.50 MB
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HRhO2_0T_Cp.dat
163 KB
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HRhO2_298K_XRD-NPD.cif
1.58 KB
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HRhO2_DSC.txt
16.49 MB
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Neutron_Bragg_DRhO2_298K_ORNL-nomad-bank1.xye
240.05 KB
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Neutron_Bragg_DRhO2_298K_ORNL-nomad-bank2.xye
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Neutron_Bragg_DRhO2_298K_ORNL-nomad-bank3.xye
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Neutron_Bragg_DRhO2_298K_ORNL-nomad-bank4.xye
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Neutron_Bragg_DRhO2_298K_ORNL-nomad-bank5.xye
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Neutron_Bragg_DRhO2_298K_ORNL-nomad-bank6.xye
240.05 KB
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Neutron_Bragg_HRhO2_298K_ORNL-nomad-bank1.xye
240.05 KB
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Neutron_Bragg_HRhO2_298K_ORNL-nomad-bank2.xye
240.05 KB
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Neutron_Bragg_HRhO2_298K_ORNL-nomad-bank3.xye
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Neutron_Bragg_HRhO2_298K_ORNL-nomad-bank4.xye
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Neutron_Bragg_HRhO2_298K_ORNL-nomad-bank5.xye
240.05 KB
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Neutron_Bragg_HRhO2_298K_ORNL-nomad-bank6.xye
240.05 KB
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Neutron_PDF_DRhO2_ftfrgr.gr
230.18 KB
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Neutron_PDF_HRhO2_ftfrgr.gr
230.18 KB
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PXRD_Na1-xRhO2_xCAN.txt
646.19 KB
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README.md
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SXRD_DRhO2__298K_Diamond-11.xye
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SXRD_HRhO2_298K_Diamond-i11.xye
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Abstract
Despite remaining enigmatic, strong hydrogen bonding provides an advanced design handle for tailoring the properties of functional materials. Here, 3R–(H/D)RhO2 delafossites (prepared by ion exchange of Na^+^ from NaRhO2) contain H/D in linear coordination with O, linking RhIIIO2 layers. Bragg and real-space X-ray and neutron scattering analysis, vibrational and solid-state NMR spectroscopy, and density functional theory–based electronic structure calculations have been employed to understand the nature of the hydrogen bonding. Despite short distances between H/D and the two O to which they are bonded, a clear double-minimum corresponding to a shorter and longer (H/D)–O distance is established. The triangular lattices formed by H/D appear to display ice-like disorder, corroborated by low-temperature heat capacity measurements.
Dataset DOI: 10.5061/dryad.1rn8pk17j
Description of the data and file structure
The data was collected to understand the structure of the materials HRhO2 and DRhO2. The collected data includes X-ray and neutron Bragg diffraction and neutron diffuse scattering data as well as solid state 1H and 2H NMR. Structural files for HRhO2 and DRhO2 are also provided.
Files and variables
Crystallographic Information Files
HRhO2
File: HRhO2_298K_XRD-NPD.cif
Description: crystallographic information file describing the structure of HRhO2. Data was generated from a joint Rietveld refinement against synchrotron X-ray and neutron Bragg diffraction data for HRhO2 at 298 K. Variables include: chemical name, measurement temperature, unit cell parameters, symmetry space group, symmetry equivalent positions, atom site labels, atom site symbols, atom site multiplicities. atom site coordinates, atom site occupancies, and atom site thermal parameters.
DRhO2
File: DRhO2_298K_XRD-NPD.cif
Description: crystallographic information file describing the structure of DRhO2. Data was generated from a joint Rietveld refinement against synchrotron X-ray and neutron Bragg diffraction data for DRhO2 at 298 K. Variables include: chemical name, measurement temperature, unit cell parameters, symmetry space group, symmetry equivalent positions, atom site labels, atom site symbols, atom site multiplicities. atom site coordinates, atom site occupancies, and atom site thermal parameters.
X-ray Bragg Diffraction Data
HRhO2
File: SXRD_HRhO2_298K_Diamond-i11.xye
Description: Synchrotron X-ray Bragg diffraction data for HRhO2 collected at 298 K at beamline i-11 at Diamond Light Source. The data is in .xye format and variables are 2-theta, Intensity, and Error.
DRhO2
File: SXRD_DRhO2__298K_Diamond-11.xye
Description: Synchrotron X-ray Bragg diffraction data for HRhO2 collected at 298 K at beamline i-11 at Diamond Light Source. The data is in .xye format and variables are 2-theta, Intensity, and Error.
Na1-xRhO2
File: PXRD_Na1-xRhO2_xCAN.txt
Description: Powder X-ray Bragg diffraction data for Na1-xRhO2 collected at 298 K in-house using Cu ka1 radiation on a Malvern PanAlytical Empyrean difftactometer. The data is in .txt format and variables are 2-theta, Q, intensity when x = 0, intensity when x = 0.2, intensity when x = 0.4, intensity when x = 0.5, intensity when x = 0.6, intensity when x = 0.8, intensity when x = 1.
Neutron Bragg Diffraction Data
HRhO2
File: Neutron_Bragg_HRhO2_298K_ORNL-nomad-bank1.xye
Description: Neutron Bragg diffraction for HRhO2 collected at 298 K on Bank 1 of the NOMAD beamline at Oak Ridge National Laboratory. The data is in .xye format and variables are TOF (s), Intensity, and Error.
File: Neutron_Bragg_HRhO2_298K_ORNL-nomad-bank2.xye
Description: Neutron Bragg diffraction for HRhO2 collected at 298 K on Bank 2 of the NOMAD beamline at Oak Ridge National Laboratory. The data is in .xye format and variables are TOF (s), Intensity, and Error.
File: Neutron_Bragg_HRhO2_298K_ORNL-nomad-bank3.xye
Description: Neutron Bragg diffraction for HRhO2 collected at 298 K on Bank 3 of the NOMAD beamline at Oak Ridge National Laboratory. The data is in .xye format and variables are TOF (s), Intensity, and Error.
File: Neutron_Bragg_HRhO2_298K_ORNL-nomad-bank4.xye
Description: Neutron Bragg diffraction for HRhO2 collected at 298 K on Bank 4 of the NOMAD beamline at Oak Ridge National Laboratory. The data is in .xye format and variables are TOF (s), Intensity, and Error.
File: Neutron_Bragg_HRhO2_298K_ORNL-nomad-bank5.xye
Description: Neutron Bragg diffraction for HRhO2 collected at 298 K on Bank 5 of the NOMAD beamline at Oak Ridge National Laboratory. The data is in .xye format and variables are TOF (s), Intensity, and Error.
File: Neutron_Bragg_HRhO2_298K_ORNL-nomad-bank6.xye
Description: Neutron Bragg diffraction for HRhO2 collected at 298 K on Bank 6 of the NOMAD beamline at Oak Ridge National Laboratory. The data is in .xye format and variables are TOF (s), Intensity, and Error.
DRhO2
File: Neutron_Bragg_DRhO2_298K_ORNL-nomad-bank1.xye
Description: Neutron Bragg diffraction for DRhO2 collected at 298 K on Bank 1 of the NOMAD beamline at Oak Ridge National Laboratory. The data is in .xye format and variables are TOF (s), Intensity, and Error.
File: Neutron_Bragg_DRhO2_298K_ORNL-nomad-bank2.xye
Description: Neutron Bragg diffraction for DRhO2 collected at 298 K on Bank 1 of the NOMAD beamline at Oak Ridge National Laboratory. The data is in .xye format and variables are TOF (s), Intensity, and Error.
File: Neutron_Bragg_DRhO2_298K_ORNL-nomad-bank3.xye
Description: Neutron Bragg diffraction for HRhO2 collected at 298 K on Bank 3 of the NOMAD beamline at Oak Ridge National Laboratory. The data is in .xye format and variables are TOF (s), Intensity, and Error.
File: Neutron_Bragg_DRhO2_298K_ORNL-nomad-bank4.xye
Description: Neutron Bragg diffraction for DRhO2 collected at 298 K on Bank 4 of the NOMAD beamline at Oak Ridge National Laboratory. The data is in .xye format and variables are TOF (s), Intensity, and Error.
File: Neutron_Bragg_DRhO2_298K_ORNL-nomad-bank5.xye
Description: Neutron Bragg diffraction for DRhO2 collected at 298 K on Bank 5 of the NOMAD beamline at Oak Ridge National Laboratory. The data is in .xye format and variables are TOF (s), Intensity, and Error.
File: Neutron_Bragg_DRhO2_298K_ORNL-nomad-bank6.xye
Description: Neutron Bragg diffraction for DRhO2 collected at 298 K on Bank 6 of the NOMAD beamline at Oak Ridge National Laboratory. The data is in .xye format and variables are TOF (s), Intensity, and Error.
Neutron Diffuse Scattering Data
HRhO2
File: Neutron_PDF_HRhO2_ftfrgr.gr
Description: Neutron diffuse scattering data collected at 298 K on the NOMAD beamline at Oak Ridge National Lab. The data is G(r) data. The variables are r in angstroms (atomic pair distance), G(r) (reduced pair distribution function value), and error g(r).
DRhO2
File: Neutron_PDF_DRhO2_ftfrgr.gr
Description: Neutron diffuse scattering data collected at 298 K on the NOMAD beamline at Oak Ridge National Lab. The data is G(r) data. The variables are r in angstroms (atomic pair distance), G(r) (reduced pair distribution function value), and error g(r).
Solid State MAS-NMR
1H NMR Data for HRhO2
File: 2.5mmMAS_1H_HRhO2.txt
Description: 1H solid state magic angle spinning NMR data for HRhO2. Data is in .txt format. The data is collected between 202.8905029296875 ppm and -197.16418006986675 ppm with 16384 data of points between those terminal values. The single column data represents the intensity measured at each data point.
2H NMR Data for DRhO2
File: 2.5mmMAS_2H_DRhO2.txt
Description: 2H solid state magic angle spinning NMR data for DRhO2. Data is in .txt format. The data is collected between 2000.0 ppm and -2000.0 ppm with 20119 data of points between those terminal values. The single column data represents the intensity measured at each data point.
1H NMR Data for the spinning rotor
File: 2.5mmMAS_1H_Rotor.txt
Description: 1H solid state magic angle spinning NMR data for an empty 2.5 mm rotor. Data is in .txt format. The data is collected between 202.8905029296875 ppm and -197.16418006986675 ppm with 16384 data of points between those terminal values. The single column data represents the intensity measured at each data point.
Heat Capacity Measurements
HRhO2
File: HRhO2_0T_Cp.data
Description: Low temperature heat capacity data measured between 1.8 K and 200 K for HRhO2 using a QuantumDesign physical property measurement system (PPMS). Variables include Time Stamp (Seconds), Comments, System Status, Puck Temp (Kelvin), System Temp (Kelvin), Field (Oersted), Pressure (Torr), Sample Temp (Kelvin), Temp Rise (Kelvin), Samp HC (J/mole-K), Samp HC Err (J/mole-K), Addenda HC (µJ/K), Addenda HC Err (µJ/K), Total HC (µJ/K), Total HC Err (µJ/K), Fit Deviation (ChiSquare), Time Const tau1 (seconds), Time Const tau2 (seconds), Sample Coupling (Percent), Debye Temp (Kelvin), Debye Temp Err (Kelvin), Cal Correction (Factor), Therm Resist (Ohms), Htr Resist (Ohms), Puck Resist (Ohms), Wire Cond (W/K), Meas Time (seconds), Temp Squared (K^2), Samp HC/Temp (J/mole-K/K), Addenda Offset HC (µJ/K).
File: HRhO2_DSC.txt
Description: High temperature heat capacity data measured between 25 C and -160 C using differential scanning calorimetry. The data is in .txt format and the variables include: time (min), temperature (celsius), heat flow (mw), delta t (microvolts), delta t zero (microvolts), t zero temperature (celsius), cell purge (ml per min), heater temperature (celsius), power delivered (w), reference junction temperature (celsius), flange temperature (celsius), heat flow phase (radians), total heat capacity (j per c), heat capacity (j per c), ln pump tank level (percent), heat flow normalized (w per g), heat capacity normalized (j per g c), total heat capacity normalized (j per g c), step time (min), heat capacity sapphire (j per g c), heat capacity polystyrene (j per g c), inverse temperature (per kelvin).
DRhO2
File: DRhO2_0T_Cp.data
Description: Low temperature heat capacity data measured between 1.8 K and 200 K for DRhO2 using a QuantumDesign physical property measurement system (PPMS). Variables include Time Stamp (Seconds), Comments, System Status, Puck Temp (Kelvin), System Temp (Kelvin), Field (Oersted), Pressure (Torr), Sample Temp (Kelvin), Temp Rise (Kelvin), Samp HC (J/mole-K), Samp HC Err (J/mole-K), Addenda HC (µJ/K), Addenda HC Err (µJ/K), Total HC (µJ/K), Total HC Err (µJ/K), Fit Deviation (ChiSquare), Time Const tau1 (seconds), Time Const tau2 (seconds), Sample Coupling (Percent), Debye Temp (Kelvin), Debye Temp Err (Kelvin), Cal Correction (Factor), Therm Resist (Ohms), Htr Resist (Ohms), Puck Resist (Ohms), Wire Cond (W/K), Meas Time (seconds), Temp Squared (K^2), Samp HC/Temp (J/mole-K/K), Addenda Offset HC (µJ/K).
File: DRhO2_DSC.txt
Description: High temperature heat capacity data measured between 25 C and -160 C using differential scanning calorimetry. The data is in .txt format and the variables include: time (min), temperature (celsius), heat flow (mw), delta t (microvolts), delta t zero (microvolts), t zero temperature (celsius), cell purge (ml per min), heater temperature (celsius), power delivered (w), reference junction temperature (celsius), flange temperature (celsius), heat flow phase (radians), total heat capacity (j per c), heat capacity (j per c), ln pump tank level (percent), heat flow normalized (w per g), heat capacity normalized (j per g c), total heat capacity normalized (j per g c), step time (min), heat capacity sapphire (j per g c), heat capacity polystyrene (j per g c), inverse temperature (per kelvin).
Code/software
All data can be opened in as .txt or .dat files.
Visualization of .cif files as 3D representations of crystal structures requires an appropriate software such as VESTA or DIAMOND.
Diffuse scattering data (.gr files) can be viewed using an appropriate refinement software such as PDFGui.
NMR data can be viewed using TopSpin.
Access information
Other publicly accessible locations of the data:
Data was derived from the following sources:
Synthesis of NaRhO2, HRhO2 and DRhO2
NaRhO2 was synthesized by combining powdered Na2CO3 (5 wt% excess, Aesar 99.95%) and Rh2O3 (Sigma 99.8%) in an agate mortar and pestle and hand grinding for 30 minutes before loading into an Al2O3 crucible and heating to 850 °C in a muffle furnace for 15 hours with a heating and cooling rate of 130 °C h^–1^
HRhO2 was synthesized from NaRhO2 (according to HxRhO2—Na1–xRHO2) by ion-exchange of Na^+^ for H^+^ using cerium ammonium nitrate (NH4)2Ce(NO3)6 (Sigma ≥ 99.99%). 50 mg of NaRhO2 was dispersed in solutions of varying molar concentrations of (NH4)2Ce(NO3)6 in ultra-pure H2O at 60 °C with continuous stirring for 100 hours.[1] Ion exchange was assumed to occur at a 1/1 molar ratio. Complete exchange was achieved using a 5/1 molar excess of (NH4)2Ce(NO3)6. The synthesis of DRhO2 was identical except for the use of D2O (Sigma 99.9 atom%) instead of H2O.
X-ray Diffraction
Synchrotron X-ray diffraction (SXRD) was performed at Diamond Light Source, U.K., on high-resolution beamline I11.[2] The patterns were recorded in the transmission mode [0.3 < Q (Å^-1^) < 8.5] using a position sensitive detector (PSD, λ = 0.824297 Å) at room temperature on samples introduced into 0.3 mm diameter borosilicate glass capillaries. Routine assessment of sample purity was carried out by powder X-ray diffraction (PXRD) out using a Panalytical Empyrean powder diffractometer fitted with a Bragg-Brentano HD module to suppress Kβ and Kα2 to provide highly monochromatic Cu Kα1 radiation (λ = 1.540562 Å). Samples were mounted on zero-background Si sample holders and measured in Bragg-Brentano geometry using a PIXcel 1D detector in the range 0.3 < Q (Å^-1^) < 7.
Neutron Powder Diffraction (NPD) and Pair Distribution Function (PDF)
Time-of-flight (TOF) neutron total scattering data was collected up to Qmax = 35 Å^-1^ at Oak Ridge National Laboratory, U.S.A., using the nanoscale-ordered materials diffractometer (NOMAD) over Banks 1–5.[3] Samples were loaded into 2 mm quartz capillaries. All data were collected at room temperature.
Refinement
Joint Rietveld refinements were carried out using TOPAS Academic (v.7).[4] Fundamental parameters of the beamline were modelled, including Lorentz-polarization, *la, lo and lh *Voigt coefficients, source-to-sample radius & slit widths, as well as characteristic instrumental profiles for TOF NOMAD data. The background was fitted manually using a 36-part linear profile for SXRD data and with a Chebyshev polynomial with between 4 and 6 coefficients for TOF NOMAD data. Peak profiles were fitted using a Pseudo-Voigt model. A simple axial model was used when modelling SXRD data and was initially constrained to 5.0 before being refined after initial peak profile fitting. Neutron PDF data was modelled and refined using the PDFfit2 and PDFgui computer program suite.[5] Structures were visualized using the Visualization for Electronic and Structural Analysis software VESTA (v.3.5.8).[6]
Wavelength Dispersive X‑Ray Fluorescence Spectrscopy (XRF)
Elemental analysis was performed using a Rigaku ZSX PrimusIV XRF spectrometer. Powdered samples were pressed into 13 mm pellets before sealing in stainless steel sample holders with a 10 mm aperture. Samples were measured under vacuum while spinning, using an acceleration voltage of 50 kV, a current of 70 mA and synthetic multilayer analyzer crystals for Na and O, and a lithium fluoride analyzer crystal for Rh. Elemental mole% was calculated from the recorded weight% using known elemental masses. Mole fractions were calculated by normalizing mole% to Rh.
Nuclear Magnetic Resonance (NMR) Spectroscopy
Approximately 15 mg of sample (pre-dried under vacuum at 120 °C for 12 hours) was packed into a 2.5 mm diameter ZrO2 magic angle spinning (MAS) rotor. Both 1H and 2H (D) NMR spectra were referenced to 1H2O and 2H2O, respectively, at 4.7 ppm. NMR spectra were acquired on a Bruker AVANCE500 high-resolution spectrometer equipped with a narrow-bore AS600 magnet charged to 500 MHz (1H) and operated at 11.7 T using a Bruker 2.5 mm 1H/X MAS probe. 1H (spin = ½) spectra were collected over 128 single-pulse scans with a spectral width of 400.05 ppm, a dwell time of 2.5 μs, and an acquisition time of 5.12 ms using a MAS frequency of 35 kHz. Quadrupolar^ 2^H (spin = 1) spectra were collected over 664 single-pulse scans with a spectral width of 3515.03 ppm, a dwell time of 1.0 μs, and an acquisition time of 2.05 ms. Various MAS frequencies between 20—30 kHz was utilized to identify the isotropic peak position. The data were processed and analyzed using the Bruker TopSpin 4.4.0 software. Quadrupolar coupling constants and asymmetric parameters were extracted from peak fitting, performed in the Bruker Sola software package.
Infrared (IR) Spectroscopy
IR spectra were collected over 128 scans using a Thermo Nicolet iS10 FTIR spectrometer equipped with a DTGS detector, KBr beamsplitter, and a HeNe laser. Spectra were measured in %transmission through a 13 mm pellet consisting of 10 mg of sample combined with 1 g of spectroscopy-grade KBr. Pellets were dried under vacuum at 120 °C for 12 hours before measurement. A blank pellet containing only KBr was also measured.
Raman Spectroscopy
Raman spectra were collected using a custom-built Horiba Scientific Jobin Yvon T64000 open-frame confocal microscope, equipped with a ×50 lens, operating with a monochromatic excitation laser wavelength of 532 nm and a liquid nitrogen cooled CCD array detector. Filters were used to reduce the laser to 10% of its original intensity to prevent damage to the samples. Spectra were calibrated using a monocrystalline Si wafer reference, which has a single peak at 521 cm^–1^.
Heat Capacity Measurements
Heat capacity measurements between 300 K and 113 K were performed by differential scanning calorimetry using a TA Instruments DSC2500. Approximately 10 mg of samples was loaded into a Tzero aluminum hermetic pan and equilibrated under N2 flow at 300 K before cooling to 113 K at 10 K min^–1^, isothermally holding for 1 minute, and then reheated heated to 300 K at 10 K min^–1^. Cycles were repeated twice. Heat capacity measurements between 1.8 K and 200 K were measured using a Quantum Design 9 T Dynacool Physical Property Measurement System (PPMS). The heat capacity pf the sample holder and APIEZON N grease (addenda) was determined prior to measuring the sample. Samples were cold‑pressed into 6 mm pellets using 6 tonnes of force and then cut into cubes of approximately 2 mm3 before being loaded into the PPMS.
Computational Methods
Distortion energetics were computed using density functional theory (DFT) as implemented in the Vienna Ab initio Simulation Package (VASP, v5.4.4).[7–9] Calculations employed the projector-augmented wave (PAW) potentials and the PBE functional^[10]^ with D3 dispersion corrections and Becke–Johnson damping (IVDW = 12).[11,12] An electronic energy convergence criterion of 10⁻⁸ eV, a force convergence threshold of 10⁻⁵ eV, and a plane-wave cutoff energy of 800 eV were used. The k-point meshes were generated automatically using a reciprocal space length parameter of 50. Experimental lattice parameters obtained from synchrotron powder X-ray and neutron diffraction were used as the initial structure, assuming R–3m** **symmetry, with hydrogen atoms placed symmetrically between oxygen atoms. Atomic positions were relaxed while keeping the cell fixed. To evaluate the energy cost of hydrogen displacement along the c-axis toward a neighboring oxygen atom, single-point energy calculations were performed on displaced geometries without further structural relaxation.