# Binary Distribution

Psi4 is available as a pre-compiled binary for Linux architectures (Mac coming soon) through Continuum Analytics, the company that produces Anaconda Python (a full-fledged scientific python environment with package manager conda) and, more particularly, Miniconda (a lightweight python distribution with same package manger conda). Some nice features for us:

- cross-platform (Linux only at present)
- no root, administrator, or sudo access required
- built with high-performance math libraries
- lightweight software stack (<100 MB w/o Psi4; <500 MB including Psi4)
- updated nightly so new features accessible
- standardizes python distribution so no need to find/install libpython packages
- add-ons (plugins, extra features requiring Fortran compiler, etc.) can be made available as conda packages

The Psi4 binary repository is at Anaconda (formerly Binstar).

For commands to get a default installation, go to Quick Installation. For more flexibility and a detailed explanation, go to Detailed Installation of Miniconda and Detailed Installation of Psi4.

## Quick Installation

Sequence of commands to get you to a working Psi4 on Linux. Installs Miniconda into `$HOME/miniconda` and the Psi4 executable into the main conda environment at `$HOME/miniconda/bin/psi4`.

    >>> bash
    >>> curl -O "http://repo.continuum.io/miniconda/Miniconda-latest-Linux-x86_64.sh"
    >>> bash Miniconda-latest-Linux-x86_64.sh -b -p $HOME/miniconda  # agrees to conda's license terms
    >>> echo "export PATH=$HOME/miniconda/bin:\$PATH" >> ~/.bashrc
    # log out, log back in so conda in path
    >>> conda update --yes --all
    >>> conda config --add channels http://conda.anaconda.org/psi4
    >>> conda install --yes psi4
    >>> psi4 "$(dirname $(which psi4))"/../share/psi/samples/scf1/input.dat -o stdout  # test installation. works b/c PSI_SCRATCH defaults to /tmp

That last command tested that `psi4` is in your path, and it’s finding all the libraries it needs. Now you need only specify a scratch directory (see Scratch Files and the ~/.psi4rc File) by replacing the placeholder in the following:

    >>> echo "export PSI_SCRATCH=/path/to/existing/writable/local-not-network/directory/for/scratch/files" >> ~/.bashrc
    # log out, log back in so variable takes effect

All done!

Note

Above commands use bash for installation and set up your environment for bash at runtime. To use csh at runtime, follow the on-screen directions at the end of the installation or consult step 7 below.

## Detailed Installation of Miniconda

0. Sanity check. If you already have Miniconda or Anaconda, skip to step 5. The whole installation takes ~5 min; reading this page takes far longer.
1. Get `bzip2`. You’ll need this slightly exotic command so run `which` to test for availability, and install from `yum`, source, etc. if unavailable. You’ll also need an internet connection for downloading; computers behind a firewall or with restricted login domains are eligible. So long as you can ssh into the computer to an account with write permissions and can connect to the internet from the computer, all is well.

    # check
    >>> which bzip2
    /usr/bin/bzip2
    >>> curl -O "http://psicode.org/psi4manual/master/introduction.html"
    >>> ls -1
    introduction.html

2. Get Miniconda installer script. Either issue the command below or download from http://conda.pydata.org/miniconda.html by clicking on the appropriate link for your OS. If you already have or would prefer to use Anaconda rather than Miniconda, that’s fine. Locate or install Anaconda, check that `conda` is in your path, and skip to step 4.

    >>> curl -O "http://repo.continuum.io/miniconda/Miniconda-latest-Linux-x86_64.sh"
    # check
    >>> ls -1
    Miniconda-latest-Linux-x86_64.sh

3. Install Miniconda. Execute the script and answer its questions, particularly your choice of installation location. You may need to replace the filename below with the correct filename for the OS/version of installer you downloaded. Execute with `bash` regardless of `csh`/`bash` shell. If you’re a `bash` user, it’s convenient to agree to its offer to prepend `conda` commands to your `PATH` in `~/.bashrc`. If you’re a `csh`/`tcsh` user, it’s convenient to do the same by hand to your `~/.tcshrc`: `setenv PATH /path/to/miniconda/bin:${PATH}`. Further directions assume that the `conda` command is in your path; you may have to log out and log back in for `which conda` to return correctly.

    >>> bash Miniconda-latest-Linux-x86_64.sh
    # check
    >>> which conda
    /path/to/miniconda/bin/conda

4. Update conda. This updates the package manager itself.

    >>> conda update conda

## Detailed Installation of Psi4

5. Subscribe to Psi4. Subscribe to our channel at http://anaconda.org/psi4 that contains the Psi4 package and several dependency packages. Make sure this shows up in your `~/.condarc` file.

    >>> conda config --add channels http://conda.anaconda.org/psi4
    # check
    >>> cat ~/.condarc
    channels:
      - http://conda.anaconda.org/psi4
      - defaults

6. Install Psi4. You can install into the main conda environment so that whenever commands `conda` or (Ana/Miniconda’s) `python` are available, then `psi4` is available, too.

    >>> conda install psi4
    # check
    >>> which psi4
    /path/to/miniconda/bin/psi4

Or, you can install into a conda environment that places Psi4 and its dependencies (including python) into a sandbox unaffected by any other software installed in Ana/Miniconda. This is recommended for developers to avoid interference between multiple versions (including github/conda versions) or to test python versions, etc.. If your main conda is not python=2.7, then Psi4 must be installed into a conda environment. In practical terms, installing into a conda environment means you can turn Psi4‘s availability on/off by switching conda environments without turning on/off the whole Ana/Miniconda installation. Below, Psi4 is installed into an environment called `p4env`. Then the environment is activated, removing the main Ana/Miniconda `bin` and adding `envs/p4env/bin` to `PATH`. The activate command only works in `bash`, so `csh`/`tcsh` will need corresponding adjustments.

    >>> conda create -n p4env psi4
    >>> source activate p4env
    # check
    >>> which psi4
    /path/to/miniconda/envs/p4env/bin/psi4

The output for either of the installation commands above looks like the following. It checks what packages are needed, gets your approval for downloading them, fetches and installs them, prints out some useful information, and runs a Psi4 test case to check that all’s well.

    >>> conda install psi4
    Fetching package metadata: ......
    Solving package specifications: .
    Package plan for installation in environment /path/to/miniconda:

    The following packages will be downloaded:

        package                    |            build
        ---------------------------|-----------------
        psi4-0.1.12                |    py27_g60a9afd        31.4 MB

    The following NEW packages will be INSTALLED:

        psi4: 0.1.12-py27_g60a9afd

    Fetching packages ...
    psi4-0.1.12-py 100% |################################################################################| Time: 0:00:01  32.49 MB/s
    Extracting packages ...
    [      COMPLETE      ] |##################################################################################################| 100%
    Linking packages ...

      Thank you for installing psi4. Additional resources:
        Website: www.psicode.org
        Inputs:  /path/to/miniconda/share/psi/samples
        Manual:  bit.ly/psi4manual
        GitHub:  https://github.com/psi4/psi4public/wiki
        Binstar: https://binstar.org/psi4
        Runtime Environment Diagnostic: /path/to/miniconda/share/psi/scripts/setenv.py

      For csh/tcsh command-line use, add to shell or ~/.tcshrc file:
        setenv PATH /path/to/miniconda/bin:$PATH
        setenv PSI_SCRATCH /path/to/existing/writable/local-not-network/disk/for/scratch/files

      For sh/bash command-line use, add to shell or ~/.bashrc file:
        export PATH=/path/to/miniconda/bin:$PATH
        export PSI_SCRATCH=/path/to/existing/writable/local-not-network/disk/for/scratch/files

    Nuclear Repulsion Energy..........................................PASSED SAPT0 Eelst.......................................................PASSED SAPT0 Eexch.......................................................PASSED SAPT0 Eind........................................................PASSED SAPT0 Edisp.......................................................PASSED SAPT0 Etotal......................................................PASSED

    [      COMPLETE      ] |##################################################################################################| 100%

7. Configure environment. Preceeding steps have placed `conda` and `psi4` in your `PATH`, either permanently through rc-files or temporarily in this terminal session. You can keep or undo these changes. For general psi4 use, you must enable the `psi4` executable to be found through any of:

> 1. prepending to `PATH` in shell, `~/.bashrc`, `~/.tcshrc`, or PBS `cmd` file
> 2. activating the conda environment (p4env above) in shell, `~/.bashrc`, or PBS `cmd` file
> 3. supplying full path to executable (shell or PBS `cmd` file)

Similarly, the scratch directory (see Scratch Files and the ~/.psi4rc File) must be specified through:

> 1. defining `PSI_SCRATCH` in shell, `~/.bashrc`, `~/.tcshrc`, or PBS `cmd` file

Suitable values for these variables have been printed to screen during installation (see last codeblock in step 6).

## Useful Commands

- Update to latest Psi4 version

      >>> conda update psi4

- Install into a conda environment “p4env” instead of “root”. Second command only works on bash; for csh/tsch, `setenv PATH /path/to/miniconda/envs/p4env/bin:$PATH` instead. This creates a sandbox with just Psi4 and python (loaded as dependency).

      >>> conda create -y -n p4env psi4
      >>> source activate p4env

- Install a particular Psi4 version

      >>> conda install psi4=0.1.12

- Uninstall Psi4 from current environment

      >>> conda remove psi4

## Troubleshooting

- If the target computer doesn’t have libc >= 2.7 (released c.2007; for reference, 2.10 is newer than 2.7; unlike most libraries, libc generally not available in multiple versions on a computer), the Psi4 conda package won’t work.

      # unsuitable computer
      >>> ldd --version
      ldd (GNU libc) 2.5
      # suitable computer
      >>> ldd --version
      ldd (GNU libc) 2.17

- It is of greatest importance that the Psi4 executable be linked against conda libpython.so not against any system libpython.so. This is arranged by setting `RPATH` to seek libraries relative to executable (thanks, conda binary relocation routine!). The conda Psi4 executable is not vulnerable to interference from your `LD_LIBRARY_PATH` settings. Below shows a well-linked executable.

  > - no libraries “not found”
  > - fundamental libraries like libc, ld-linux, pthreads found system libraries to link against
  > - libpython linked against conda python not system python
  > - libm is linked against conda or system
  > - blas, c++, and gcc libraries are absent because statically linked

  >     >>> conda install conda-build  # needed for next command
  >     >>> conda inspect linkages psi4
  >     python-2.7.9-2:
  >         libpython2.7.so.1.0 (lib/libpython2.7.so.1.0)
  >     system-5.8-1:
  >         libm.so.6 (lib/libm.so.6)
  >     system:
  >         libc.so.6 (/lib64/libc.so.6)
  >         libdl.so.2 (/lib64/libdl.so.2)
  >         libpthread.so.0 (/lib64/libpthread.so.0)
  >         librt.so.1 (/lib64/librt.so.1)
  >         libutil.so.1 (/lib64/libutil.so.1)
  >         linux-vdso.so.1 ()
  >     not found: