Supplementary material to the manuscript "The nuclear-spin-forbidden rovibrational transitions of water from first principles" by Andrey Yachmenev, Guang Yang, Emil Zak, Sergei Yurchenko, and Jochen Küpper, J. Chem. Phys., submitted. arXiv:2203.07945 The data set contains hyperfine (spin-rovibrational) energies and dipole transition spectrum of water molecule (H216O), calculated using variational approach TROVE and RichMol, and included spin-rotational and spin-spin hyperfine interactions. In addition, the data set includes HDF5-type richmol database file h2o_p48_j40_rovib.h5 (see https://github.com/CFEL-CMI/richmol) containing rovibrational energies, matrix elements of nuclear spin-rotation, nuclear spin-spin, electric dipole, and electric quadrupole tensor operators of H216O, calculated using variational approach TROVE. h2o_exomol_F.states and h2o_exomol_F.trans - hyperfine linelist of water stored in the ExoMol format (see, e.g., J. Molec. Spectrosc., 327, 73-94 (2016)). The two files contain a set of hyperfine states with assignments and a set of dipole transitions (Einstein A-coefficients), respectively. The states in h2o_exomol_F.states file are arranged by quantum number of total angular momentum F = I + J (spin + rotation) in ascending order. h2o_exomol_J.states and h2o_exomol_J.trans - contain same data as h2o_exomol_F.states and h2o_exomol_F.trans files, except that the states in h2o_exomol_J.states file are arranged by rotational quantum number (J) in ascending order. h2o_p48_j40_rovib.h5 - Richmol HDF5 database file for H216O containing rovibrational energies (in cm-1), matrix elements of nuclear spin-rotation (in kHz), spin-spin (in kHz), molecular electric dipole moment (in Debye), and molecular electric quadrupole moment (in a.u.) operators. For details on how to read this file, see Richmol GitHub repository and Richmol documentation (or contact Andrey Yachmenev at andrey.yachmenev@cfel.de). ortho_para_transitions.txt - table with strongest predicted ortho-para transitions in H216O at T = 296 K with the 10−36 cm/molecule intensity cut-off. An example of hyperfine energies and hyperfine dipole spectrum calculation for water using h2o_p48_j40_rovib.h5 file from this repository may be found in the Richmol GitHub repository's examples folder: https://github.com/CFEL-CMI/richmol/tree/develop/examples/hyperfine Structure of h2o_exomol_F.states and h2o_exomol_J.states files: Column No. Kind Meaning 1 int state ID number 2 float hyperfine state energy relative to the ZPE, in cm-1 3 int state degeneracy 4 int value of F quantum number (total spin-rotational angular momentum) 5 str state symmetry in C2v 6 int value of J quantum number (total rotational angular momentum) 7 str symmetry of state's rotational component in C2v 8 int value of ka quantum number (a-axis projection of rotational angular momentum) 9 int value of kc quantum number (c-axis projection of rotational angular momentum) 10 int value of v1 vibrational quantum number 11 int value of v2 vibrational quantum number 12 int value of v3 vibrational quantum number 13 int value of I quantum number (total nuclear spin) 14 float reference rovibrational state energy (i.e., without hyperfine effects) relative to the ZPE, in cm-1 Structure of h2o_exomol_F.trans and h2o_exomol_J.trans files: Column No. Kind Meaning 1 int ID number of final transition state (col. no. 1 in h2o_exomol_F.states or h2o_exomol_J.states file) 2 int ID number of initial transition state (col. no. 1 in h2o_exomol_F.states or h2o_exomol_J.states file) 3 float Einstein A-coefficient, in s-1 4 float Transition wavenumber, in cm-1

This work has been supported by the Deutsche Forschungsgemeinschaft (DFG) through the priority program "Quantum Dynamics in Tailored Intense Fields" (QUTIF, SPP1840, YA 610/1, KU 1527/3) and the clusters of excellence "Center for Ultrafast Imaging" (CUI, EXC 1074, ID 194651731) and "Advanced Imaging of Matter" (AIM, EXC 2056, ID 390715994). This work was also supported in part through the Maxwell computational resources operated at Deutsches Elektronen-Synchrotron DESY, Hamburg, Germany. Sergei Yurchenko acknowledges support from the UK Science and Technology Research Council (STFC) No. ST/R000476/1 and the European Research Council under the European Union's Horizon 2020 research and innovation programme through Advance Grant number 883830. The authors acknowledge the use of the Cambridge Service for Data Driven Discovery (CSD3), part of which is operated by the University of Cambridge Research Computing on behalf of the STFC DiRAC HPC Facility (www.dirac.ac.uk). The DiRAC component of CSD3 was funded by BEIS capital funding via STFC capital grants ST/P002307/1 and ST/R002452/1 and STFC operations grant ST/R00689X/1. DiRAC is part of the National e-Infrastructure. Guang Yang gratefully acknowledges the financial support by the China Scholarship Council (CSC).