[AMBER] wrap problem with QM/MM

From: Covington, Cody Lance <cody.l.covington.Vanderbilt.Edu>
Date: Sun, 27 Sep 2015 20:49:38 +0000

Hello all

During adQMMM calculations I am getting a box size error after many steps:
....
NSTEP = 195200 TIME(PS) = 391.400 TEMP(K) = 297.25 PRESS = 141.5
Etot = -19531.3004 EKtot = 4292.8913 EPtot = -23824.1917
BOND = 3.6755 ANGLE = 19.8954 DIHED = -0.7372
1-4 NB = 4.5501 1-4 EEL = -0.1530 VDWAALS = 3375.4160
EELEC = -25996.3407 EHBOND = 0.0000 RESTRAINT = 0.0000
PM6ESCF= -1230.4979
EKCMT = 2158.4788 VIRIAL = 1930.6103 VOLUME = 74580.0076
                                                    Density = 0.9702
Ewald error estimate: 0.2651E-01
------------------------------------------------------------------------------

  ****************************************************
  ERROR: QM region + cutoff larger than box dimension:
  QM-MM Cutoff = 7.0000
   Coord Lower Upper Size Radius of largest sphere inside unit cell
     X -16.108 9.839 25.947 20.941
     Y -13.744 10.130 23.874 20.941
     Z -27.990 27.560 55.549 20.941
  ****************************************************
SANDER BOMB in subroutine QM_CHECK_PERIODIC<qm_mm.f>
QM region + cutoff larger than box
cannot continue, need larger box.

I have noticed before that if part of the QM region is outside of the box initially, it may not image some atoms properly and give this error, so I centered my QM region to the center of the box before running the MD. But now it seems my solute has diffused to the periodic boundary during MD and is causing problems. Does anyone know of a way of fixing this?

Thank You
Cody Covington
_______________________________________________
AMBER mailing list
AMBER.ambermd.org
http://lists.ambermd.org/mailman/listinfo/amber
Received on Sun Sep 27 2015 - 14:00:03 PDT
Custom Search