# What's new in GTPack 1.1

GTPack version 1.1 was released on March 1st, 2020. Besides several bug fixes, GTPack 1.1 comes with a new sub package GTRepresentationTheorySG allowing for the calculation of representation matrices and character tables of space groups. It furthermore provides novel functionality for electronic structure calculations.

Handling and representation theory of space groups

GTPack 1.1 offers a few new modules to handle symmetry elements of space groups.

GTSGgmat | multiplies two space group elements |

GTSGOrderOfElement | gives the order of a space group element |

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Additionally, GTPack 1.1 provides several new modules to analyze the group structure of space groups..

GTSGClasses | multiplies two space group elements |

GTSGGetInvSubGroup | gives the order of a space group element |

GTSGLeftCosets | gives the left cosets of the factor group G/T (G being a space group, T the group of pure lattice translations) with respect to a subgroup |

GTSGRightCosets | gives the right cosets of the factor group G/T (G being a space group, T the group of pure lattice translations) with respect to a subgroup |

GTSGCosetRepresentative | determines a coset representative for a left coset decomposition of the factor group G/T (G being a space group, T the group of pure lattice translations) into a normal subgroup of index 2 or 3 |

_{1}/c (#14). We calculate the corresponding basis vectors of the reciprocal lattice using GTReciprocalBasis. Then we install the space groups using GTInstallGroup.

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The probably most important modules for space groups which were introduced in GTPack 1.1 concern the calculation of the irreducible representations and character table of space groups.

GTSGCharacterTable | gives the character table of a space group |

GTSGGetIreps | gives the character table and representation matrices of a space group |

Exploring orbital characters in electronic structure calculations

GTPack 1.1 offers a new functionality to highlight the orbital character in electronic structure calculations.

GTPartialDOS | calculation of partial densities of states (TB Hamiltonians) |

GTFatBandsPlot | plots orbital character of a band structure (TB Hamiltonians) |

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Besides the new modules presented above, some existing modules where extended. For GTClusterManipulate, the new method "Impurities" was added, which allows to substitute a randomly chosen selection of one atomic species within a cluster by impurities. GTDensityOfStatesRS was extended to allow for eigenvalues of an electronic structure calculation as an input. This way, computationally demanding eigenvalue problems can be solved outside of Mathematica.