QEISPACK provides routines for solving the eigenvalues and eigenvectors of a matrix in the quadruple precision. It is based on the fortrun90 eispack library.
Note that the test has NOT been completed yet.
- gfortrun (>=4.7)
(or the other fortrun compiler which supports quadruple precision math library such as relatively newer ifort)
gfortrun -c qeispack.f90
- the evaluation for the energy gap (tunnel splitting) in a Hamiltonian system by using double precision Lapack (numpy), Mathematica (100 digits precision) and qeispack (quadruple precision).
- the eigenvalues for an unitary matrix
- test_qeispack_prb1.f90 is a test program that calculates eigenvalues and eigenvectors of a complex general matrix.
- now preparing...
Compile:
gfortrun -o test qeispack.o test_qeispack_prb1.f90
QEISPACK is freely-available software package and it is distribued under GNU Lesser General Public License (GNU LGPL)
Author has been supported by JSPS KAKENHI Grants No. 16K17767