README file
Data Set Title: “Data for the characterization of diarylethene-based photoswitches with core and valence photoabsorption and photoemission spectroscopies”
Data Set Author/s: 
Nenov Artur (Unibo), ORCID (0000-0003-3071-5341); 
Stefano Severino (Politecnico di Miano), ORCID (0000-0002-9607-8077);

Data Set Contributor/s: 
Nenov Artur (Unibo), ORCID (0000-0003-3071-5341);
Stefano Severino (Politecnico di Miano), ORCID (0000-0002-9607-8077);
Marta Pini (Politecnico di Miano), ORCID (0000-0002-3772-4542);

Data Set Contact Person/s: 
Nenov Artur (Unibo), ORCID (0000-0003-3071-5341), artur.nenov@unibo.it;
Stefano Severino (Politecnico di Miano), ORCID (0000-0002-9607-8077), marta.pini@polimi.it;

Data Set License: this data set is distributed under a Creative Commons Attribution (CC BY), https://creativecommons.org/licenses/by/4.0/deed.en

Publication Year: 2026
Funding: The ultimate Time scale in Organic Molecular opto-electronics, the ATTOsecond (TOMATTO), Funded by the European Commission under the European Research Council (ERC), Horizon 2020 programme, grant ID 951224 https://doi.org/10.3030/951224 
Data set Contents
The data set consists of:
 •	Archive with computational data on BTF6 
“BTF6.zip”
 •	Archive with computational data on PTF6 
“PTF6.zip”
 •	Archive with computational data on TF6 
“TF6.zip”
 •	Archive with experimental spectra on BTF6 and PTF6 
“Experimental_data.zip”
 •	README file 
“README.rtf”
Data set Documentation
Abstract
The data set contains experimental and computational raw data for the PES and the NEXAFS and XPS spectra at the K-edge of carbon, as well as at the L23 edge of sulfur of two systems – BTF6 and PTF6 – presented and discussed in the paper “Characterization of of diarylethene-based photoswitches with core and valence photoabsorption and photoemission spectroscopies”, published in the Journal of Chemical Physics 10.1063/5.0323110. The experimental data contains raw spectra as well as polished spectra with the background subtracted. The computational data contains input and output files of the electronic structure calculations of the valence, valence-ionized, core-ionized and core-excited manifolds of the two samples.

Content of the files: 
 •	each of the two files BTF6.zip and PTF6.zip contains following folder structure (differences are listed in the Notes)
 o	parallel
 •	OR
 •	opt.gjf (input file for the MP2 optimization performed with G16)
 •	opt.out (output file for the MP2 optimization)
 •	NEXAFS
 o	C(carbon)
 •	C??
 •	core-to-pi (calculations with π/π* MOs in the active space for describing 1s to π* transitions)
 o	valence.input (input file for computing GS)
 o	valence.out (output file for GS calculation)
 o	valence.RasOrb (molecular orbital file with optimized RASSCF orbitals of GS)
 o	core.input (input file for computing core-ES)
 o	core.out (output file for core-ES calculation)
 o	core.RasOrb (molecular orbital file with optimized RASSCF orbitals of core-ES)
 o	core.rasscf.molden (file for visualization of core-ES molecular orbitals)
 o	tdm.input (input file for computing transition dipole moments between valence and core-excited states)
 o	tdm.out (output file)
 o	local.LocOrb (molecular orbital file with localized core-orbitals)
 o	BTF6/PTF6_OR_C??.xyz (Cartesian coordinates of geometry to use in all calculations)
 o	WF_SS-??-RASPT2_TDM_S0.dat: (summary of the electronic structure of the core-excited states)
 o	S(sulfur)
 •	rasscf_singlet.input (input file for computing singlet GS and core-ES at CASSCF level)
 •	rasscf_singlet.out (output file of singlet GS and core-ES calculation)
 •	rasscf_singlet.RasOrb (molecular orbital file with optimized RASSCF orbitals for singlet states)
 •	rasscf_singlet.rasscf.molden (file for visualization of singlet state molecular orbital)
 •	pt2_singlet.input (input file for computing CASPT2 energy correction for singlet core-ES)
 •	pt2_singlet.out (output file for singlet core-ES)
 •	rasscf_triplet.input (input file for computing triplet core-ES at CASSCF level)
 •	rasscf_triplet.out (output file of triplet core-ES calculation)
 •	rasscf_triplet.RasOrb (molecular orbital file with optimized RASSCF orbitals for triplet states)
 •	rasscf_triplet.rasscf.molden (file for visualization of triplet state molecular orbital)
 •	pt2_triplet.input (input file for computing CASPT2 energy correction for triplet core-ES)
 •	pt2_triplet.out (output file for triplet core-ES)
 •	tdm.input (input for computing transition dipole moments between GS and core-ES with spin-orbit coupling)
 •	tdm.out (output file)
 •	BTF6/PTF6_OR_S.xyz (Cartesian coordinates of geometry to use in all calculations)
 •	WF_Spin-adiab_??_TDM_vS0.dat (summary of the electronic structure of the spin-adiabatic states)
 •	PES
 o	CAS_39_20 (input files for SS-PT2/SA-20-CASSCF(39,20))
 •	rasscf.input (input file for computing valence ionized states at CASSCF level)
 •	rasscf.out (output file of valence ionized states calculation)
 •	rasscf.RasOrb (molecular orbital file with optimized RASSCF orbitals for valence ionized states)
 •	rasscf.rasscf.molden (file for visualization of valence ionized state molecular orbital)
 •	pt2.input (input file for computing CASPT2 energy correction for valence ionized states)
 •	pt2.out (output file for valence ionized states)
 •	GS.input (input file for computing GS)
 •	GS.out (output file of GS calculation)
 •	dyson.input (input for computing transition dipole moments between GS and valence ionized states)
 •	dyson.out (output file)
 •	BTF6/PFT6_OR.xyz (Cartesian coordinates of geometry to use in all calculations)
 •	MO1-20.png (bitmap image file of the occupied orbitals in the active space)
 •	WF_SS-20-RASPT2_Dy_S0.dat (summary of the electronic structure of the valence ionized states)
 o	anti-parallel
 •	OR/CR (Open-Ring or Closed-Ring structure; CR present only for BTF6)
 •	opt.gjf (input file for the MP2 optimization performed with G16)
 •	opt.out (output file for the MP2 optimization)
 •	NEXAFS
 o	C(arbon)
 •	C??
 •	core.png (bitmap image file of the core orbital)
 •	core-to-pi (calculations with π/π* MOs in the active space for describing 1s to π* transitions)
 o	valence.input (input file for computing GS)
 o	valence.out (output file for GS calculation)
 o	valence.RasOrb (molecular orbital file with optimized RASSCF orbitals of GS)
 o	core.input (input file for computing core-ES)
 o	core.out (output file for core-ES calculation)
 o	core.RasOrb (molecular orbital file with optimized RASSCF orbitals of core-ES)
 o	core.rasscf.molden (file for visualization of core-ES molecular orbitals)
 o	LUMO.png (bitmap images of the LUMO orbitals from the calculation of the core-excited states)
 o	tdm.input (input file for computing transition dipole moments between valence and core-excited states)
 o	tdm.out (output file)
 o	local.LocOrb (molecular orbital file with localized core-orbitals)
 o	BTF6/PTF6_OR/CR_C??.xyz (Cartesian coordinates of geometry to use in all calculations)
 o	WF_SS-??-RASPT2_TDM_S0.dat: (summary of the electronic structure of the core-excited states)
 •	core-to-other (calculations with Rydberg and σ* MOs in the active space for describing 1s to and Rydberg σ* transitions; available only for OR)
 o	valence.input (input file for computing GS)
 o	valence.out (output file for GS calculation)
 o	valence.RasOrb (molecular orbital file with optimized RASSCF orbitals of GS)
 o	core.input (input file for computing core-ES)
 o	core.out (output file for core-ES calculation)
 o	core.RasOrb (molecular orbital file with optimized RASSCF orbitals of core-ES)
 o	core.rasscf.molden (file for visualization of core-ES molecular orbitals)
 o	tdm.input (input file for computing transition dipole moments between valence and core-excited states)
 o	tdm.out (output file)
 o	BTF6/PTF6_OR/CR_C??.xyz (Cartesian coordinates of geometry to use in all calculations)
 o	WF_SS-??-RASPT2_TDM_S0.dat: (summary of the electronic structure of the core-excited states)
 o	S(ulfur)
 •	rasscf_singlet.input (input file for computing singlet GS and core-ES at CASSCF level; available only for OR)
 •	rasscf_singlet.out (output file of singlet GS and core-ES calculation)
 •	rasscf_singlet.RasOrb (molecular orbital file with optimized RASSCF orbitals for singlet states)
 •	rasscf_singlet.rasscf.molden (file for visualization of singlet state molecular orbital)
 •	pt2_singlet.input (input file for computing CASPT2 energy correction for singlet core-ES)
 •	pt2_singlet.out (output file for singlet core-ES)
 •	rasscf_triplet.input (input file for computing triplet core-ES at CASSCF level)
 •	rasscf_triplet.out (output file of triplet core-ES calculation)
 •	rasscf_triplet.RasOrb (molecular orbital file with optimized RASSCF orbitals for triplet states)
 •	rasscf_triplet.rasscf.molden (file for visualization of triplet state molecular orbital)
 •	pt2_triplet.input (input file for computing CASPT2 energy correction for triplet core-ES)
 •	pt2_triplet.out (output file for triplet core-ES)
 •	tdm.input (input for computing transition dipole moments between GS and core-ES with spin-orbit coupling)
 •	tdm.out (output file)
 •	BTF6/PTF6_OR/CR_S.xyz (Cartesian coordinates of geometry to use in all calculations)
 •	WF_SA-??-RASSCF_S0.dat (summary of the electronic structure of the singlet GS and core-ES)
 •	WF_Spin-adiab_??_TDM_vS0.dat (summary of the electronic structure of the spin-adiabatic states)
 •	2p1-3.png (bitmap image file of the core orbital)
 •	MO4-11.png (bitmap image file of the virtual orbitals in the active space)
 •	XPS
 o	C(arbon)
 •	C??
 •	valence.input (input file for computing valence GS)
 •	valence.out (output file for GS calculation)
 •	valence.RasOrb (molecular orbital file with optimized RASSCF orbitals of GS)
 •	core.input (input file for computing core-ionized states)
 •	core.out (output file for core-ionized states calculation)
 •	core.png (bitmap image file of the core orbital)
 •	core.RasOrb (molecular orbital file with optimized RASSCF orbitals for core-ionized states)
 •	core.rasscf.molden (file for visualization of core-ionized molecular orbital)
 •	dyson.input (input file for computing Dyson intensities between valence and core-ionized states)
 •	dyson.out (output file)
 •	local.LocOrb (molecular orbital file with localized core-orbitals)
 •	BTF6/PTF6_OR/CR_C??.xyz (Cartesian coordinates of geometry to use in all calculations)
 •	WF_SS-??-RASPT2_Dy_S0.dat: (summary of the electronic structure of the core-ionized states)
 o	S(ulfur)
 •	doublet.input (input file for computing core-ionized states)
 •	doublet.out (output file of core-ionized states)
 •	doublet.RasOrb (molecular orbital file with optimized RASSCF orbitals)
 •	doublet.rasscf.molden (file for visualization of core-ionized state molecular orbital)
 •	valence.input (input file for computing GS)
 •	valence.out (output file of GS calculation)
 •	valence.RasOrb (molecular orbital file with optimized RASSCF orbitals)
 •	dyson.input (input for computing Dyson intensities between valence and core-ionized states with spin-orbit coupling)
 •	dyson.out (output file)
 •	BTF6/PTF6_OR/CR_S.xyz (Cartesian coordinates of geometry to use in all calculations)
 •	WF_SS-3-RASPT2_Dy_S0.dat (summary of the electronic structure of the doublet core-ionized states)
 •	WF_Spin-adiab_7_TDM_vS0.dat (summary of the electronic structure of the core-ionized states with spin-orbit effects)
 •	PES
 o	CAS_39_20 (input files for SS-PT2/SA-20-CASSCF(39,20))
 •	rasscf.input (input file for computing valence ionized states at CASSCF level)
 •	rasscf.out (output file of valence ionized states calculation)
 •	rasscf.RasOrb (molecular orbital file with optimized RASSCF orbitals for valence ionized states)
 •	rasscf.rasscf.molden (file for visualization of valence ionized state molecular orbital)
 •	pt2.input (input file for computing CASPT2 energy correction for valence ionized states)
 •	pt2.out (output file for valence ionized states)
 •	GS.input (input file for computing GS)
 •	GS.out (output file of GS calculation)
 •	dyson.input (input for computing transition dipole moments between GS and valence ionized states)
 •	dyson.out (output file)
 •	BTF6/PFT6_OR/CR.xyz (Cartesian coordinates of geometry to use in all calculations)
 •	MO1-20.png (bitmap image file of the occupied orbitals in the active space)
 •	WF_SS-20-RASPT2_Dy_S0.dat (summary of the electronic structure of the valence ionized states)
 o	full-pi (input files for SS-PT2/SA-8-RASSCF(13,4,4;7,0,7) and XMS-PT2/SA-8-RASSCF(13,4,4;7,0,7), only available for OR)
 •	rasscf.input (input file for computing valence ionized states at CASSCF level)
 •	rasscf.out (output file of valence ionized states calculation)
 •	rasscf.RasOrb (molecular orbital file with optimized RASSCF orbitals for valence ionized states)
 •	rasscf.rasscf.molden (file for visualization of valence ionized state molecular orbital)
 •	ss-pt2.input (input file for computing SS-CASPT2 energy correction for valence ionized states)
 •	ss-pt2.out (output file for valence ionized states)
 •	xms-pt2.input (input file for computing XMS-CASPT2 energy correction for valence ionized states)
 •	xms-pt2.out (output file for valence ionized states)
 •	GS.input (input file for computing GS)
 •	GS.out (output file of GS calculation)
 •	GS.RasOrb (molecular orbital file with optimized RASSCF orbitals for GS)
 •	dyson_ss-pt2.input (input for computing transition dipole moments between GS and valence ionized states at the SS-CASPT2 level)
 •	dyson_ss-pt2.out (output file)
 •	dyson_xms-pt2.input (input for computing transition dipole moments between GS and valence ionized states at the XMS-CASPT2 level)
 •	dyson_xms-pt2.out (output file)
 •	BTF6/PFT6_OR.xyz (Cartesian coordinates of geometry to use in all calculations)
 •	WF_SS-8-RASPT2_Dy_S0.dat (summary of the electronic structure of the valence ionized states at the SS-CASPT2 level)
 •	WF_XMS-8-RASPT2_Dy_S0.dat (summary of the electronic structure of the valence ionized states at the XMS-CASPT2 level)
 •	the file TF6.zip contains following folder structure
 o	XPS
 •	doublet.input (input file for computing core-ionized states)
 •	doublet.out (output file of core-ionized states)
 •	doublet.RasOrb (molecular orbital file with optimized RASSCF orbitals)
 •	doublet.rasscf.molden (file for visualization of core-ionized state molecular orbital)
 •	valence.input (input file for computing GS)
 •	valence.out (output file of GS calculation)
 •	valence.RasOrb (molecular orbital file with optimized RASSCF orbitals)
 •	dyson.input (input for computing Dyson intensities between valence and core-ionized states with spin-orbit coupling)
 •	dyson.out (output file)
 •	local.LocOrb (molecular orbital file with localized core-orbitals)
 •	TF6_S.xyz (Cartesian coordinates of geometry to use in all calculations)
 •	WF_SS-3-RASPT2_Dy_S0.dat (summary of the electronic structure of the doublet core-ionized states)
 •	WF_Spin-adiab_7_TDM_vS0.dat (summary of the electronic structure of the core-ionized states with spin-orbit effects)
 •	file Experimental_data.zip contains raw data for PES, NEXAFS and XPS spectra of BTF6 and PTF6 at the K-edges of carbon and oxygen, as well as at the L23 edge of sulfur, as well as Matlab script for plotting the data

File specifics
 o	Following a list of files’ extension and ways to edit / run / visualize content
 o	.gjf: ASCII input file for performing electronic structure calculations which can be visualized with any text editor; calculations are to be executed with Gaussian 16 (https://gaussian.com/)
 o	.input: ASCII input files for performing electronic structure calculations which can be visualized with any text editor; calculations are to be executed with OpenMolcas (https://gitlab.com/Molcas/OpenMolcas/) 
 o	.out: ASCII files with the outputs of the electronic structure calculations which can be visualized with any text editor;
 o	WF...dat: ASCII files with summary of the electronic structure calculations which can be visualized with any text editor;
 o	.RasOrb: ASCII files with molecular orbital coefficients, a necessary input for running CASSCF calculation with OpenMolcas 
 o	.rasscf.molden: ASCII files which can be opened for visualizing molecular orbitals with Pegamoid (https://pypi.org/project/Pegamoid/) or with with Molden (https://www.theochem.ru.nl/molden/) 
 o	.png: bitmap images of geometries and molecular orbitals that can be opened with any bitmap viewer
 o	.xyz: Cartesian coordinates of geometries which can be opened with Molden (https://www.theochem.ru.nl/molden/) 
 o	Each file in Experimental_data.zip has following format: two column ASCII file with “,” separator, 1st column: energy range (units: eV); 2nd column: intensity (arb. units)

Notes 
 •	The carbon labels in the carbon K-edge folders differ from the ones used in the paper.
Methodologies 
•        The simulated XPS and NEXAFS spectra presented in the main article can be obtained from the computational data in this data set by means of eqs. 1 and 2 from the article “Characterization of the hemithioindigo photoswitch and its derivatives with x-ray photoabsorption and photoemission spectroscopies” (doi: 10.1063/5.0271164). For convenience, binding energies and Dyson intensities, required to simulate the PES and XPS spectra, as well as transition energies and transition dipole moments, required to simulate NEXAFS spectra, have been extracted from the calculations and can be found in the WF_Spin-adiab_??_TDM_vS0.dat and WF_SS-??-RASPT2_Dy_S0.dat files (the symbol “??” Indicates a variable number of states). Additional parameters (broadenings and shifts) are listed in the paper for each spectroscopy and edge.