DIIS

Activate the DIIS based optimization procedure for BAND [Edit on GitHub]

Subsections

• DIIS_INFO

Keywords

• CHECK_DIIS

• MAX_SD_STEPS

• MAX_STEPS

• MAX_STEPSIZE

• NO_LS

• NP_LS

• N_DIIS

• STEPSIZE

Keyword descriptions

CHECK_DIIS

Type: logical
Default: T
Lone keyword: T

Description: Performs a series of checks on the DIIS solution in order to accept the DIIS step. If set to .FALSE. the only check performed is that the angle between the DIIS solution and the reference vector is less than Pi/2. Can be useful if many DIIS steps are rejected. [Edit on GitHub]

MAX_SD_STEPS

Type: integer
Default: 1

Description: Specify the maximum number of SD steps to perform before switching on DIIS (the minimum number will always be equal to N_DIIS). [Edit on GitHub]

MAX_STEPS

Type: integer
Default: 100

Description: Specify the maximum number of optimization steps [Edit on GitHub]

MAX_STEPSIZE

Type: real
Default: 2.00000000E+000
Usage: MAX_STEPSIZE

Description: Maximum stepsize used for the line search, sometimes this parameter can be reduced to stabilize the LS for particularly difficult initial geometries [Edit on GitHub]

NO_LS

Type: logical
Default: F
Lone keyword: T

Description: Does not perform LS during SD. Useful in combination with a proper STEPSIZE for particularly out of equilibrium starting geometries. [Edit on GitHub]

NP_LS

Type: integer
Default: 2
Usage: NP_LS

Description: Number of points used in the line search SD. [Edit on GitHub]

N_DIIS

Type: integer
Default: 7
Aliases: NDIIS
Usage: N_DIIS 4

Description: Number of history vectors to be used with DIIS [Edit on GitHub]

STEPSIZE

Type: real
Default: 1.00000000E+000
Usage: STEPSIZE

Description: Initial stepsize used for the line search, sometimes this parameter can be reduced to stabilize DIIS [Edit on GitHub]