Firefly and PC GAMESS-related discussion club

 
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Alexander Bednyakov
al123458@mail.ru

>>Here is my $ZMAT group:
>> INPUT CARD> $zmat dlc=.t. auto=.t.
>> INPUT CARD> ifzmat(1)=1,18,29 fvalue(1)=6.0 nonvdw(1)=18,29 $end

>>Roman.
>>

>The following is a very brief description of several new keywords of the $ZMAT group.

>AUTOFV (default .true.) means to generate fvalue array automatically. Any user input of fvalue is thus ignored. This option is especially useful for relaxed PES scans in DLC.

>DLCTOL (default 1.0d-5) is the threshold used at several stages during DLC generation, as well as to impose geometrical constrains. Normally you do not need to alter it, however, in some cases setting it to, say, 1d-7 can help generating required number of linearly independent DLC coordinates.

>IFRZAT is the array of atom numbers you want to freeze during geometry optimization using DLC. More precisely, the distances between all chosen atoms will be frozen, however, they will be allowed to rotate and translate as the single, united group (rigid body).

>Hope this helps
>Alex Granovsky
>


Dear, Dr. Alex Granovsky

It seems like FVALUE and IFZMAT don't work exactly the same as in GAMESS(US). In the latter you can generate Z-matrix once with a bond length, for example, 0.98, and then generate several input files where you change this length (for example, 0.96, 0.94 and so on) using only FVALUE without generating new Z-matrix manually and programm automatically change the whole Z-matrix depending on this FVALUE, as Roman has already said. Was trying to do the same thing in Firefly turning AUTOFV option off but it doesn't work. Does any possibility for such an approach still exist in Firefly ?

Here is an example for my $ZMAT:
DLC=.TRUE. AUTOFV=.false.
IFZMAT(1)=1,3,1, 1,6,4, 1,9,7, 1,12,10, 1,15,13, 1,18,16
FVALUE(1)=0.96,0.96,0.96,0.96,0.96,0.96

Yours sincerely,
Alexander