Extended Hückel

Extended Hückel program

The extended Hückel program (v1.0-fortran) with basis sets of Slater-type orbitals is a simple code for calculating total energy of a molecule and its basic properties, such as coefficients, Milliken populations, gross atomic orbital populations, and so on. The overlap integrals are estimated by the Trapezoidal rule in real space, such as Jacobi method for diagonalization, bubble sort, and matrix multiplication.

(Note: The speed of calculations is slow due to S integrals in real space, not in k-space.)

1. Download

2. How to compile?

3. How to run a job?

4. Examples and results

5. References

6. README

1. Download :

1. Package : eh_1.0

2. README

3. Input files : (1) H-He, (2) CH4, (3) H2CO.

2. How to compile?

    (a) go to lib/ to compile library

    cd lib

    make

    (b) compile the main program in the source/ directory

    cd source

    make

3. How to run a job ?

    For example, key in " ./eh_1.0 HHe.ehi "

    HHe.ehi is the name of the input file for a H-He molecule.

4. Basic examples and results:

1. H-He

1. Figure 1(a). The input data of a H-He molecule.

• 1. Figure 1(b). The output data of a H-He molecule.

1. CH4

• 1. Figure 3. The printed data of a formaldehyde (H2CO) molecule.

5. Reference

• Attila Sazbo, Neil S. Ostlund, “Modern Quantum Chemistry: Introduction to Advanced Electronic Structure Theory“.