MOLPRO

43 VIBRATIONAL FREQUENCIES (FREQUENCIES) 336
LOW=value
Threshold for printing low vibrations in cm −1 (default 150). If a value
> 0 is given, frequencies below this value are not printed.
43.3 Saving the hessian and other information (SAVE)
SAVE,options
The following options can be given:
hessian=record
FREQ=record
TASK=record
Save hessian to record (same effect as option HESSREC). By default
the hessian is saved on record 5300.2.
Save frequencies and normal modes to record (same effect as option
FREQREC). By default the frequencies are saved on record 5400.2.
Save task information for possible restart of hessian calculation to
record (same effect as option TASKREC). By default the frequencies
are saved on record 5500.2.
43.4 Restarting a hessian/Frequency calculation (START)
START,options
The following options can be given:
HESSIAN=record
TASK=record
Read hessian from record record (same effect as option READHESS).
Read task information from record record and restart numerical hessian
calculation (same effect as option RESTART).
43.5 Coordinates for numerical hessian calculations (COORD)
COORD,type
type can be one of the following:
UNIQUE
3N
Use symmetry-unique displacements in the numerical calculation of
the hessian (default).
Don’t use symmetry-unique displacements (not recommended).
43.6 Stepsizes for numerical hessian calculations (STEP)
[STEP,rstep]
determines the step size of the numerical differentiation of the energy or the gradient. The
default step size is rstep=0.01 a.u.
43.7 Numerical hessian using energy variables (VARIABLE)
VARIABLE,name;
Defines a variable name which holds the energy value to be used for computing the hessian
using finite differences. By default, this is ENERGY(1) as set by the most recent program.
For other other variables which can be used see section 42.2.17. Note that numerical hessians
cannot be computed when dummy atoms holding basis functions are present.