12.4.1.4.18. podcoupling

Electronic coupling between two covalently bonded fragments of one converged ground-state DFT calculation, by projection-operator diabatization (POD2): each fragment’s Fock sub-block is diagonalized separately and the coupling is read from the off-diagonal block, with the Lowdin correction for the overlap of the two fragment orbitals (as in DIPRO, Baumeier et al., PCCP 12, 11103 (2010)). For non-bonded fragments use the coupling tool (DIPRO). The following table contains the defaults input options for the calculator, The default OPTIONAL means this option is switched off, if no input is given. REQUIRED arguments have to be specified, otherwise an error is thrown.

Property Name	Default Value	Description	Valid Input
job_name	system	Input file name without extension, also used for intermediate files
orb_file	system.orb	Converged ground-state DFT calculation (orb file) of the bonded supermolecule
fragment_A		Atom indices (0-based) of fragment A, e.g. ‘0:5’ or ‘0 1 2 3 4 5’ (same syntax as cdft.indices)
fragment_B		Atom indices (0-based) of fragment B, disjoint from fragment_A
levA	1	Number of occupied and of virtual orbitals of fragment A, counted from the HOMO/LUMO gap (as levA of the coupling tool): 1 covers HOMO and LUMO, 2 covers HOMO-1 to LUMO+1, etc.	int+
levB	1	As levA, for fragment B	int+
write_cube_files	false	Write a cube file for each fragment orbital covered by levA/levB	bool
xsteps	25	Grid points in x for the cube files (as in gencube)	int+
ysteps	25	Grid points in y for the cube files (as in gencube)	int+
zsteps	25	Grid points in z for the cube files (as in gencube)	int+
padding	6.5	Distance of the cube grid from the molecule (as in gencube)	float+

Note

An xml file containing the defaults for the podcoupling calculator can be created via -p podcoupling -o FILENAME command line options `