[molpro-user] MPI error: Reply to Christan Stemmle

[Nike Dattani]

Dear Christian,
Your error looks to be exactly the same as the one described by Hans
Hogreve in the link you sent. Since you have an error with the MPI
Broadcasting, can you tell us what MPI library was used when you installed
MOLPRO? FCIQMC is parallelized with MPI, so at the stage where you got this
error, it's trying to send a copy of some data to all cores that you have
available. This data delivery (MPI broadcast) is done by the MPI library
that was used to build your version of MOLPRO. The installation manual says
"Intel MPI, Bull MPI, MPICH2, and Open MPI have been tested", so if you can
check that you're using one of these, and the versions are compatible with
everything else that was used, you might find the source of your problem.

Alternatively, if you turn off MPI and try on a single core of a single
node you should not get this error, but the calculation will be
approximately a factor of N slower where N is the number of cores you have
available, because the speed-up when going through the loop over
determinants in FCIQMC is (almost) linear in N, and you would be losing one
of the main benefits of FCIQMC.

With best wishes!
Nike

----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 3 Apr 2018 10:37:14 +0200
> From: Christan Stemmle <christian.stemmle at fu-berlin.de>
> To: molpro-user at molpro.net
> Subject: [molpro-user] FCIQMC Error
> Message-ID: <1d0f2c05-f67c-bbb9-35f5-46d5327e5cb8 at fu-berlin.de>
> Content-Type: text/plain; charset=utf-8; format=flowed
>
> Hello Molpro Users,
>
> I want to test and run some FCIQMC calculations. To get started I took the
> first example from the manual (http://www.molpro.net/info/
> current/examples/nn_fciqmc.com) and submitted a molpro calculation
> (Version 2015.1). However I keep getting the following error message:
>
> Fatal error in PMPI_Bcast: Invalid datatype, error stack:
> PMPI_Bcast(1610): MPI_Bcast(buf=0x3ca7c8c0, count=104, MPI_DATATYPE_NULL,
> root=0, MPI_COMM_WORLD) failed
> PMPI_Bcast(1570): Datatype for argument datatype is a null datatype
>
> I also tested the other examples, without any success.
> This is very similar to a previously reported issue (
> http://www.molpro.net/pipermail/molpro-user/2017-July/006999.html): same
> error message but different numbers. However, this one did not receive any
> (public) answer.
>
> Can anyone help me out?
>
> best regards
> Christian Stemmle
>
> ------------------------------
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.molpro.net/pipermail/molpro-user/attachments/20180404/c715859f/attachment.html>