C.1 Q-Chem Text Input Summary

C.1.3 Keyword: $basis

(June 30, 2021)

The format for the user–defined basis section is as follows:

$basis
X 0
L K scale
α1 C1Lmin C1Lmin+1 C1Lmax
α2 C2Lmin C2Lmin+1 C2Lmax
αK CKLmin CKLmin+1 CKLmax
****
$end

where X Atomic symbol of the atom (atomic number not accepted) L Angular momentum symbol (S, P, SP, D, F, G) K Degree of contraction of the shell (integer) scale Scaling to be applied to exponents (default is 1.00) ai Gaussian primitive exponent (positive real number) CiL Contraction coefficient for each angular momentum (non–zero real numbers).

Atoms are terminated with **** and the complete basis set is terminated with the $end keyword terminator. No blank lines can be incorporated within the general basis set input. Note that more than one contraction coefficient per line is one required for compound shells like SP. As with all Q-Chem input deck information, all input is case–insensitive.