Sparse Keyword
Last Update: 12/31/2000

Use sparse matrix storage for performance enhancement of large calculations (above around 400 atoms) [324]. The keyword's option allows you to specify the cutoff value for considering matrix elements to be zero.

Loose
Sets the cutoff to 5 * 10^-5.

Medium
Sets the cutoff to 5 * 10^-7. This is the default for semi-empirical methods.

Tight
Sets the cutoff to 1 * 10^-10. This is the default for DFT methods.

N
Sets the cutoff to 1 * 10^-N.

AVAILABILITY Energies and gradients for AM1, PM3, MNDO and DFT methods.

FMM