hanada-yasutaka / qeispack

quadruple precision eispack

QEISPACK

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.

Requirement

• gfortrun (>=4.7)

(or the other fortrun compiler which supports quadruple precision math library such as relatively newer ifort)

Usage

gfortrun -c qeispack.f90

Related multiple precision programs

• mpmath
• MPACK

Demo

• 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

Examples and Tests:

• 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

Licence

QEISPACK is freely-available software package and it is distribued under GNU Lesser General Public License (GNU LGPL)

Acknowledgments

Author has been supported by JSPS KAKENHI Grants No. 16K17767