From chemistry-request@ccl.net Fri Aug 1 14:16:58 2003 Received: from pilsener.srv.ualberta.ca (pilsener.srv.ualberta.ca [129.128.5.19]) by server.ccl.net (8.12.8/8.12.8) with ESMTP id h71IGw47007563 for >ccl.net>; Fri, 1 Aug 2003 14:16:58 -0400 Received: from maildrop.srv.ualberta.ca (maildrop [129.128.5.73]) by pilsener.srv.ualberta.ca (8.12.9/8.12.9) with ESMTP id h71IG8BI029239 for >ccl.net>; Fri, 1 Aug 2003 12:16:28 -0600 (MDT) Received: from webmail.ualberta.ca (webmail.srv.ualberta.ca [129.128.5.105]) by maildrop.srv.ualberta.ca (8.12.9/8.12.9) with ESMTP id h71IFsLd026909 for >ccl.net>; Fri, 1 Aug 2003 12:15:58 -0600 (MDT) X-WebMail-UserID: tluchko Date: Fri, 1 Aug 2003 12:19:53 -0600 Sender: tluchko >ualberta.ca> From: tluchko >ualberta.ca> To: chemistry<>ccl.net X-EXP32-SerialNo: 00003228 Subject: CHARMM: Crystal problem Message-ID: <3F2C5AE4<>webmail.ualberta.ca> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-Mailer: WebMail (Hydra) SMTP v3.61.08 Hello, I've been try to run some PBC simulations under CHARMM but I keep running into the following error: ***** LEVEL -5 WARNING FROM ***** ***** Crystal metric matrix is singular. ****************************************** BOMLEV ( -2) IS REACHED - TERMINATING. WRNLEV IS 5 Not every system does this but a large number do. Of those that do some are ok if I increase the initial box size by a couple of Angstroms in each dimension. All of the systems that give me problems do so after I solvate them. Does anyone have any suggestions as to what is causing this problem and how to fix it? Thank you, Tyler .oOOo..oOOo..oOOo..oOOo..oOOo..oOOo..oOOo..oOOo..oOOo..oOOo..oOOo..oOOo..oOOo. Tyler Luchko Masters Student Deparment of Physics 780-492-5519 University of Alberta tluchko<>ualberta.ca Edmonton, Alberta, Canada p442a