About gMultiwfn

gMultiwfn is an unofficial and (maybe) enhanced gfortran port of the popular wavefunction analyzing software Multiwfn developed by Tian Lu. This gfortran port is maintained by Xing Yin (stecue@gmail.com). Email Xing or open an issue on the github (strongly preferred!) on the github if you find a bug or need a new additional feature. You can also discuss related topics in the official Chinese forum for Multiwfn.

Binary Packages

RPM packages for openSUSE, Fedora and CentOS are built on the OBS platform (thanks to openSUSE!). Go to this gMultiwfn download page and select the OS, the download instructions for your system will show.

Compile From Source

gMultiwfn uses the standard GNU Build System. If you are familiar with ./configure and make && make install, building gMultiwfn is very easy. The following steps sevre as a general guideline and you can make changes accordingly if you are an expert on GNU autotools or have special needs.

Download the package

The source tarball can be found here. Please use the link displayed as gMultiwfn-3.4.0-0.tar.gz, not the links displayed as

Source code (zip)

Source code (tar.gz)

The laters are the "git" versions of the source code generated by GitHub automatically and they are for developers only.

Requirements

• You can use either Intel Fortran Compiler (ifort) or gfortran.
• If you choose ifort, make sure Intel Math Kernel Library (Intel MKL) is installed. If not sure, you can just try to continue building first because MKL is usually bundled and installed with ifort by default.
• If you choose gfortran, make sure you have lapack/blas and their development files (usually named as lapack-devel and blas-devel or lapack-dev and blas-dev in your distro's repository) installed. The optimized LAPACK/BLAS implementations (see below) will not be searched and used by the configure script during building.

Basic build protocol

1. Open a terminal and go to the directory where the tarball is downloaded, or move the tarball to your current directory.
2. Unzip and extract files from the source tarball. If the name of the tarball is gMultiwfn-3.4.0-1.tar.gz, the command would be:

tar -xvzf gMultiwfn-3.4.0-0.tar.gz

3. Make a separate build direcotry under the original "root" source directory:

cd gMultiwfn-3.4.0-0
mkdir build

4. Run the configure script to configure the installation path and generate the make files. The binary (Multiwfn) will always be installed to a bin directory but you can specify the where the bin direcory is located. For $HOME/bin, type:

../configure --prefix=$HOME

5. make and install. You can specify the number of processes to be used by make. For example, to fully utilize the power of a 4-core/8-thread CPU, type:

make -j8 && make install

6. Now Multiwfn should be found at $HOME/bin. Add $HOME/bin to your PATH environment variable if not added before. Type Multiwfn to see if the building is successful.

Switch To A Faster LAPACK/BLAS Implementation

gMultiwfn is dynamically linked to lapack and blas by default. The reference implementations of lapack and blas are usually the slowest and in a lot of cases they can be safely replaced by optimized implementations such as OpenBLAS and ATLAS using the steps described below. Note that installing OpenBLAS or ATLAS is beyond the scope of this document and please refer to your distro's manual on that information.

Use update-alternatives to make a system-wide change

Use man or refer to your disto's manual on the usage. You may need root user's privilege to run this command.

Use LD_PRELOAD to change just for gMultiwfn

LD_PRELOAD is the enviroment variable to force the dynamic linker in Linux to use a certain version of shared libraries (.so files). It provides a quick solution to try a new libarary without being asked for root user privilege. Assuming OpenBLAS is installed to /path/to/libopenblas.so, LD_PRELOAD=/path/to/libopenblas.so Multiwfn will start Multiwfn with the optimized OpenBLAS. To avoid typing the extra letters every time, simply add alias gMultiwfn='LD_PRELOAD=/path/to/libopenblas.so Multiwfn' to your bash initialization file (usually ~/.bashrc). gMultiwfn will be equivalent to LD_PRELOAD=/path/to/libopenblas.so Multiwfn' for all new termnal windows.

(Must Read) Differences Between Multiwfn And gMultiwfn

1. gMultiwfn does not contain the GUI which is base on the closed-source DISLIN library.
2. gMultiwfn supports the OMP_NUM_THREADS enviroment variable and the traditional nthreads parameter from settings.ini or the interactive input (the hidden option 1000 at the main menu). nthreads has the higher priority. Only when nthreads is set to 0 (which is the default setting without a settings.ini file), OMP_NUM_THREADS determines the number of threads to use. For example, to use 8 threads without settings.ini, just run

OMP_NUM_THREADS=8 gMultiwfn

3. Depending on the version of OpenBLAS, you may need to use the serial version or the OpenMP version of OpenBLAS with OMP_NUM_THREADS. See discussions here and here.