Re: Re: problem with TIP4P on nightly version

From: Brian Radak (
Date: Sun Feb 02 2020 - 14:31:58 CST

This error has to do with how lone pairs are detected and placed. I thought
I had cleaned a lot of this up when adding support for colinear lone pairs,
but it's possible that I missed something or broke something that I didn't

Are you using Xplor or Amber inputs? If the former, do you have explicit
lone pair declarations in the PSF? If the latter, have you done anything to
the atom masses? Have you set any non default flags in your input (e.g.
Lonepairs on)?


On Fri, Jan 31, 2020, 10:51 AM Peter Freddolino <> wrote:

> Sorry to ask a potentially obvious question, but can you please confirm
> that running the *exact same* TIP4P system in version 2.13 vs the nightly
> build gives different results? Your email only says that you used some
> unspecified TIP4P system in namd 2.13 and it worked ok. If this is the same
> system, can you provide a small test case that reproduces the behavior that
> you are seeing?
> Thanks,
> Peter
> On Fri, Jan 31, 2020 at 10:00 AM Laura Lopes <>
> wrote:
>> It looks like my message was cutted because of the link. Sorry everyone,
>> that's the original one!
>> On Fri, 31 Jan 2020, 11:22 Laura Lopes, <>
>> wrote:
>>> Dear all,
>>> I installed the nightly build version and I get an error message when I
>>> try to run a TIP4P system.
>>> *FATAL ERROR: must have same number of LP hosts as lone pairs*
>>> Apparently this error existed in an old NAMD version.
>>> Does someone have an idea on how to solve this ? I was running version
>>> 2.13 with TIP4P systems and everything was fine.
>>> Best,
>>> Laura

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