[CPMD-list] constraints

[Axel Kohlmeyer]

On Fri, 01 Nov 2002 18:59:42 +0100  Phineus Markwick wrote:

> Hallo cpmd-list,

hi phineus,

> 
> I am trying to program a new type of constraint in cpmd. As it is a 
> quasi-distance constraint (based on several multiple distances), I have 
> followed in principle the distance constraint program that already exists.
> 
> I introduce the new constraint in CONINP.F, defining the name of the new 
> constraint and the atomic numbers that occur in the input line, the 
> constraint "distance" and the LSHOVE value.
> 
> In CNSTFC.F, I call the program FILLC(...) to read in the appropriate 
> atomic coordinates, and then call the two constraint subroutines that 
> are in CONSTR.F (funcconstraint.F and diffconstraint.F).
> 
> In CONSTR.F I have already introduced the two new subroutines 
> funcconstraint and diffconstraint.
> 
> When I run cpmd with the new constraint, the program happliy runs 
> through CONINP.F, CNSTFC.F and CONSTR.F. The program reads in all the 
> atomic coordinates and runs through the two subroutines funccontraint 
> and diffconstraint.

are you sure? the following stack(?) trace suggests, that the error
occurs somewhere at line 118 of the file cnstfc.f. pehaps on calling
or returning from a subroutine/function call.

cheers,
	axel.

> 
> Using the same terminology as in the existing constraint subroutines 
> funcd and diffd, my new constraint subroutines generate both fd (fd 
> =d-RO, the difference between the actual distance and the constraint 
> distance) and the vector dR.
> At this point the program immediately stops with the error output:
> 
> 
> forrtl: error (75): floating point exception
>     0: __FINI_00_remove_gp_range [0x3ff81a6de38]
>     1: __FINI_00_remove_gp_range [0x3ff81a76e60]
>     2: __FINI_00_remove_gp_range [0x3ff800d5120]
>     3: cnstfc_ [./cnstfc.f: 118, 0x1201cb028]
>     4: detdof_ [./detdof.f: 191, 0x1201c9b10]
>     5: mdmain_ [./mdmain.f: 119, 0x1201daa00]
>     6: mdpt_ [./mdpt.f: 124, 0x1201d9ff0]
>     7: cpmd_ [./cpmd.f: 120, 0x12003dac4]
>     8: cpmd_stuttgart_ [./cpmd.f: 3, 0x12003d590]
>     9: main [for_main.c: 203, 0x1203fc66c]
>    10: __start [0x12003d3b8]
> time: command terminated abnormally.
> 
> real   15.8
> user   3.0
> sys    2.6
> 
> The last line in the output file is the number of degrees of 
> freedom.(which is correct).
> 
> This error message suggests to me that at some point the program is 
> being asked to do something stupid like divide some number by zero.
> This is not occuring in the two subroutines funcconstraint and 
> diffconstraint, but at some later point in the program. The only two new 
> variables generated by these two programs are fd and the vector dR, and 
> these seem to be O.K.
> 
> So, are there any other programs that I need to edit or introduce?
> 
> In particular, I am concerned by the fact that for this new constraint, 
> I have at no point defined either fd or dR other than to state that they 
> exist as variables in the programs funcconstraint and diffconstraint.
> 
> I would appreciate any help or comments,
> best regards,
> Phineus Markwick.
> 
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> 

--

=======================================================================
Axel Kohlmeyer      e-mail:  axel.kohlmeyer at theochem.ruhr-uni-bochum.de
Lehrstuhl fuer Theoretische Chemie          Phone: ++49 (0)234/32-26673
Ruhr-Universitaet Bochum - NC 03/53         Fax:   ++49 (0)234/32-14045
D-44780 Bochum                   http://www.theochem.ruhr-uni-bochum.de
=======================================================================
If you make something idiot-proof, the universe creates a better idiot.