XMVB 3.0 is released!

Published time : 2017-07-18

We are pleased to anounce that XMVB is now updated to Version 3.0. The XMVB manual is also updated and the PDF version has been uploaded to the website.
Following algorithms/techniques are implemented in XMVB to make XMVB more powerful:

  • Integrals, exspecially ERIs, can be computed directly in XMVB calcualtions now, instead of reading ERIs from file prepared with a third program. This may accelerate the computations when large number of basis functions are involved.
  • Cholesky decomposition (CD) of ERIs is supported by XMVB 3.0 which may accelerate VB calculations a lot when there are many inactive orbitals involved. Now VBSCF calculations can be carried out for more than one thousand basis functions.
  • Tensor-based formalism for valence bond theory is omplemented in XMVB 3.0, which accelerates VBSCF calculations with larger active space.
  • State average VBSCF (SA-VBSCF) computations can be done nwo with XMVB by a simple keyword.

Please refer to our release note for more information.

Release Note

PREINT now supports more basis sets

Published time : 2017-04-27

We are pleased to anounce that PREINT now supports more basis sets.
PREINT is a utility for XMVB 2.1 to prepare integrals. It now supports following basis sets:

3-21G 3-21G* 3-21++G 3-21++G*
6-31G 6-31+G 6-31+G* 6-31++G 6-31++G* 6-31++G** 6-31G* 6-31G**
6-311G 6-311+G 6-311+G* 6-311+G(2D,P) 6-311+G** 6-311++G 6-311++G* 6-311++G** 6-311++G(2D,2P) 6-311G* 6-311G**
cc-pCVDZ cc-pCVTZ
cc-pVDZ cc-pVTZ cc-pVQZ
aug-cc-pCVDZ aug-cc-pCVTZ
aug-cc-pVDZ aug-cc-pVTZ aug-cc-pVQZ

Only elements with shells up to F are supported now. We will make more basis sets and elements supported later.
The latest PREINT is available in "dev" and "beta" branches of XMVB.
All XMVB users are welcome to ask for the utility if interested.

XMVB 2.1 utility updae : 6d25d

Published time : 2015-07-02

We are pleased to anounce that the utility of XMVB 2.1, 6d25d, has been updated. The XMVB 2.l manual is also updated and the PDF version has been uploaded to the website.
6d25d is a utility for XMVB 2.1 to provide integrals based on harmonic rather than cartisian functions. It supported only D functions at first and now F basis functions are also supported.
Considering the fact that the sequential of F functions are different in Gaussian/PREINT and GAMESS-US, 6d25d supports the input with either type with a simple option in the command.
All XMVB users are welcome to ask for the utility if interested.

Parallel XMVB beta version is available now !

Published time : 2014-10-20

We are glad to announce that the beta version of parallel XMVB is available now. The parallel version is a stand-alone program rather than the GAMESS-US module. The integral of parallel XMVB is compatible with integral obtained from GAMESS-US module XMVB.
The parallel XMVB is based on OPENMP and can be run as parallel job within one node. Since it is beta version, there may be still some bugs in the program. Application for the XMVB program and feedback of the bugs in XMVB program are the most welcome.

Parallel Version of XMVB Is Under Development

Published time : 2013-12-01

The parallel version of XMVB, XMVB-MPI, is now under development.
The goal of XMVB-MPI project is to make it possible that XMVB is available for large and complicated systems. Currently, XMVB can work only in serial mode, which may not be too slow if the system under study is large. XMVB-MPI is believed to be a solvation for such problem.

XMVB standalone distribution : rewritten in F90

Published time : 2013-08-30

The stand-alone distribution of XMVB is now rewritten in Fortran 90. With the support of dynamic memory allocation of Fortran 90, stand-alone distribution is much more flexible in memory consuming and hence supports more machines, especially those with small amount of memory than GAMESS-US module distribution. With small active space, i.e., 4 active orbitals and 4 active electrons for cyclobutadiene, stand-alone distribution works fine on a notebook with only 2GB memory.
The integral of stand-alone distribution is completely compatible with GAMESS-US module distribution. So one may obtain the integral by GAMESS-US module distribution and then run XMVB jobs with stand-alone distribution.

GUI of XMVB Is Under Development

Published time : 2013-06-30

The GUI (Graphic User Interface) of XMVB, XMVB-GUI, is now under development. With XMVB-GUI, one can easily create XMVB input file and analyze results of XMVB calculations, including viewing output file content, visualizing XMVB structures and VB orbitals. It will be very helpful for XMVB starters.
Windows version of XMVB-GUI will be released first. XMVB-GUI for other platforms will be released later.