SPIN (.param)

Keyword type

Real

Description

This keyword determines the initial value for the number of unpaired electrons in a spin-polarized calculation. This value may be optimized during the CASTEP calculation depending on the values of SPIN_FIX and FIX_OCCUPANCY.

The SPIN keyword cannot be used in conjunction with either of NUP or NDOWN keywords.

Default

0 when the total number of electrons in the system is even.

1 when the total number of electrons in the system is odd.

Example

SPIN : 3

See Also:

SPIN_FIX
FIX_OCCUPANCY
NUP
NDOWN
CASTEP keyword glossary
CASTEP parameters keywords