Este archivo ha sido creado el 25-07-2025 por Rocio Sanchez de Armas GENERAL INFORMATION ------------------ 1. Dataset title: Dataset for the preparation of the manuscript “Spin-crossover Fe(II) complexes on a surface: a mixture of low-spin and high-spin molecules at low temperature from quantum-chemistry calculations”, publish in Inorganic Chemistry Frontiers 2022, 9, 753-760. DOI: 10.1039/D1QI01487K 2. Authorship: Name: Rocio Sanchez de Armas Institution: Universidad de Sevilla Email:rociosa@us.es ORCID: 0000-0002-2384-4893 Name: Carmen Jimenez Calzado Institution: Universidad de Sevilla Email:calzado@us.es ORCID: 0000-0003-3841-7330 DESCRIPTION ---------- 1. Dataset language: English 2. Abstract: This dataset supports the theoretical study of the deposition of a monolayer of an Fe(II) spin-crossover [Fe((3,5-(CH3)2Pz)3BH)2] complex on a Au(111) substrate, with different proportions of HS/LS molecules. Our results indicate that there exist both thermodynamic and kinetic factors favoring the presence of a mixed HS/LS state at low temperature. The pure LS phase and a mixed spin state with 1/3 of HS molecules are close in energy, and the transition from this mixed spin state to the pure LS is hindered by the highest activation barrier in the transition from the HS to LS phase. The presence of the surrounding molecules of the 2D superstructure facilitates the transition from the LS to HS state and the interaction between the molecular layer and the surface increases with the proportion of HS molecules, in line with the epitaxial growth of the monolayer and its similarities with the (01 ) plane of the HS bulk molecular crystal. The density of states resulting from the rPBE calculations is used to simulate STM images. An excellent agreement is found between the simulated STM images for the mixed state with 1/3 of HS molecules and the images acquired at a constant height for a submonolayer of this Fe(II) complex on Au(111). 3. Keywords: Spin-crossover (SCO) complexes; [Fe((3,5-(CH3)2Pz)3BH)2]; deposition; surface; Au(111); monolayer; STM; magnetic properties; DFT; VASP files; INCAR; CONTCAR; optimized structures 4. Date of data collection: 25-11-2021 5. Publication Date: 08-09-2025 6. Grant information: Grant Agency: MCIN/AEI/10.13039/501100011033/FEDER/UE Grant Number: PGC2018-101689-B-I00 Grant Agency: MCIN/AEI/10.13039/501100011033/FEDER/UE Grant Number: PID2021-127674NB-I00 ACCESS INFORMATION ------------------------ 1. Creative Commons License of the dataset: CC BY-NC-ND 2. Dataset DOI: https://doi.org/10.12795/11441/176774 3. Related publication: Spin-crossover Fe(II) complexes on a surface: a mixture of low-spin and high-spin molecules at low temperature from quantum-chemistry calculations, Inorganic Chemistry Frontiers 2022, 9, 753-760. DOI: 10.1039/D1QI01487K Correction: Inorganic Chemistry Frontiers 2024, 11, 4032-4032. DOI: 10.1039/d4qi90039a VERSIONING AND PROVENANCE --------------- 1. Last modification date: 25-07-2025 2. Were data derived from another source?: No METHODOLOGICAL INFORMATION ----------------------- 1. Description of the methods used to collect and generate the data: We have studied the deposition of a monolayer of the [Fe((3,5-(CH3)2Pz)3BH)2] complex on Au(111) by means of periodic density functional theory (DFT) based calculations, using the VASP (Vienna ab initio simulation package) code, in the frame of the projector-augmented wave (PAW) method. In all the calculations, the revised Perdew–Burke–Ernzerhof (rPBE) functional is employed. A cutoff of 500 eV has been established for the plane-wave basis sets representing the valence electrons, and all the calculations refer to the Γ-point of the Brillouin zone. The lattice parameters of the Au bulk were optimized, and the resulting parameters a = b = c = 2.97 Å have been used to model the (111) surface. During the optimization of the surface, only the atomic positions of the upper layer were relaxed, while the lattice parameters were restrained to those optimized for the bulk. The 2D molecular superstructure deposited on gold is modelled with unit cells containing three Fe–pz molecules, where a slab with 144 atoms distributed in 4 layers (19.47 × 15.43 Å) represents the Au(111) surface. In the z direction, the slabs are separated by 30 Å vacuum that prevents interactions in this direction. The relaxation of the electronic degrees of freedom is stopped when the energy change between two steps is smaller than 10−6 eV, while the optimization reaches convergence when all the Hellmann–Feynman forces are lower than 0.025 eV Å−1. The NUPDOWN option is used to set the difference between the number of electrons in the up and down spin components, Nα–Nβ, and obtain solutions that represent different fractions of HS molecules on the monolayer. Hence, NUPDOWN is forced to be 0 for the pure LS phase, 4 for the monolayer with 1/3 of HS molecules, 8 for a monolayer with 2/3 of HS molecules and 12 for the pure HS phase. Once optimized, the NUPDOWN restriction is removed, and the total energy of each solution is recalculated. A residual magnetic moment is found on the Fe LS centers (|mFe| ∼ 0.3μβ) once the NUPDOWN restriction is removed. To evaluate the zero-point energy (ZPE) of the HS and LS molecules deposited on Au(111), reduced Hessian matrices (i.e., considering only the displacements of the atoms of the Fe–pz molecule and the first layer of the gold surface) were calculated at the Γ point for a single Fe–pz molecule deposited on Au(111). Finally, we have simulated the STM images of the deposited monolayer with two different bias voltages (−1 and 1 V) in the frame of the Tersoff–Hamann approximation. FILE OVERVIEW ---------------------- 1. Explain the file naming conversion: 2. File list: File name: HSHSHS.CONTCAR HSHSHS.INCAR LSHSHS.CONTCAR LSHSHS.INCAR LSLSHS.CONTCAR LSLSHS.INCAR LSLSLS.CONTCAR LSLSLS.INCAR Description: input parameters and optimized geometries of a monolayer of the [Fe((3,5-(CH3)2Pz)3BH)2] complex adsorbed on Au(111). As the supercell contains 3 molecules, 4 spin combinations hasve been considered: HSHSHS, LSHSHS, LSLSHS and LSLSLS. 3. Relationship between files: 4. File format: text 5. If the dataset includes multiple files, specify the directory structure and relationships between the files: The dataset includes 4 directories with the optimized geometries and input files for the following systems: HSHSHS, LSHSHS, LSLSHS and LSLSLS.