On Wed, Nov 19, 2008, Chin, Keith B wrote:
>
> Suppose rather than a box lattice, I wish to apply PBC for hex lattice,
> where a=4.516, b= 4.516, c = 7.435, alpha = 90, beta = 90, gamma = 120.
Amber cannot do this small a unit cell. Basically, the box size must be at
least twice the cutoff + "skin" (usually 1 to 2 Ang.) Your only real
alternative is to simulate several unit cells as one "supercell". A cell size
of 18 Ang. is about the practical minimum for Amber.
>
> Ewald PARAMETER RANGE CHECKING:
> parameter skinnb+cutoffnb: (nonbond list cut) has value 0.12000E+02
> This is outside the legal range
> Lower limit: 0.00000E+00 Upper limit: 0.58665E+01
> Check ew_legal.h
This is basically saying (in jargon) what I said above. It looks like you are
setting the cutoff to 10, which is too large -- you should probably stick to
the default of 8.
...good luck...dac
-----------------------------------------------------------------------
The AMBER Mail Reflector
To post, send mail to amber.scripps.edu
To unsubscribe, send "unsubscribe amber" (in the *body* of the email)
to majordomo.scripps.edu
Received on Fri Dec 05 2008 - 16:04:55 PST
