LICENSE.txt

“Fourier-Bessel Particle-In-Cell (FBPIC)”, Copyright (c) 2016,
University of Hamburg and The Regents of the University of California,
through Lawrence Berkeley National Laboratory (subject to receipt of
any required approvals from the U.S. Dept. of Energy).  All rights
reserved."

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are
met:

(1) Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.

(2) Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.

(3) Neither the name of the University of Hamburg, University of
California, Lawrence Berkeley National Laboratory, U.S. Dept. of Energy
nor the names of its contributors may be used to endorse or promote
products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE

You are under no obligation whatsoever to provide any bug fixes,
patches, or upgrades to the features, functionality or performance of
the source code ("Enhancements") to anyone; however, if you choose to
make your Enhancements available either publicly, or directly to
Lawrence Berkeley National Laboratory, without imposing a separate
written license agreement for such Enhancements, then you hereby grant
the following license: a non-exclusive, royalty-free perpetual license
to install, use, modify, prepare derivative works, incorporate into
other computer software, distribute, and sublicense such enhancements
or derivative works thereof, in binary and source code form.