PC GAMESS-related discussion club

rabin rabe
rabbipaf@yahoo.com

my downloaded binary is pcg701. however, in my output file it's PC gamess v 7.0 build # 3970. is this the one you're referring to?


rabin

On Fri Mar 16 '07, Alex Granovsky wrote
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>Hi Rabin,

>what is the PC GAMESS version and build number you are using? Is this the official PC GAMESS v. 7.0 or 7.0.1? I'm asking as the interesting thing concerning your input is that in the release version, there is no more than 18 atoms allowed to be frozen using ifrzat, otherwise, the program will bomb. This is related with the fact that ifrzat is internally converted to constrains added to IFZMAT array, and there is no more than 50 primitive coordinates which can be frozen in the generic release version. The point is that prior to the official PC GAMESS v. 7.0 due to minor mistake in code parsing $zmat group, unrecognized keywords of $zmat group would be silently ignored. Thus, if you are using a prerelease version of the PC GAMESS v. 7.0, there can be a situation when your ifrzat group is simply ignored.

>By the way, you can also use ifreez array in the $statpt group to freeze cartesian coordinates directly (although) less efficient computationally as compared with the use of ifrzat array.

>Regards,
>Alex Granovsky
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>On Fri Mar 16 '07, rabin rabe wrote
>-----------------------------------
>>dear dr. granovsky,
>>
>>
>>i intend to put a diatomic oxygen on my molecule via geometry optimization. during the optimization, i freeze my molecule using the IFRZAT while the diatomic oxygen is unconstrained. i understand that IFRZAT would freeze the atoms of my molecule while it could rotate (translational, rotational) as a whole molecule. my result was not the one i was expecting. some atoms of my molecule are still moving (changing bond lengths).

>>my question is: is IFRZAT applicable to geometry optimization or with surface scan alone? if its not, how would i do geometry optimization by freezing my molecule and an unconstrained diatomic oxygen. hereunder is my sample input file:
>>
>>
>> $CONTRL SCFTYP=RHF RUNTYP=OPTIMIZE ECP=READ MAXIT=400
>>  DFTTYP=B3LYP MULT=1 UNITS=ANGS irest=0 $END
>> $SYSTEM TIMLIM=99999 MEMORY=10000000 $END
>> $STATPT HESS=GUESS METHOD=QA OPTTOL=0.00001 NSTEP=999 $END

>>  
>> $DATA
>> FeC20N4H12  mult1
>>C1
>>IRON       26.0      0.0140994348     -0.0219464561      0.0279605201
>>   SBKJC
>>
>>CARBON      6.0      2.4422241720      2.4094759939      0.0387209696
>>   N311      6

>>..........
>>
>>
>>H-ECP  
>>H-ECP
>>O-ECP  NONE
>>O-ECP
>> $END

>> $ZMAT DLC=.T. AUTO=.T.
>>       IFRZAT(1)=1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,
>>              22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37
>> $END

>>any advice would be appreciated.
>>
>>
>>thanks in advance

>>rabin