FHI-aims CHANGELOG

How to understand this CHANGELOG (and FHI-aims):

Here, we list a rough overview of recent changes in FHI-aims. A complete record of is available directly through the FHI-aims GitLab. Every user is welcome and encouraged to gain access to the FHI-aims GitLab. The GitLab repository is also the location where bug fixes, improvements etc. will be made available.

A final general note: Please have a look at the growing Wiki in the FHI-aims GitLab. You’ll find helpful information about compiling and running FHI-aims: https://aims-git.rz-berlin.mpg.de/aims/FHIaims/-/wikis/home

Changes since release version 231212

Several small changes/fixes:

• Setting packed_matrix_threshold=0d0 for computation dipole matrix or momentum matrix.
• Using the same number of states across all task for ill-conditioned basis
• Fix allocation of some arrays when relaxation is requested for sr-lr hybrid functionals
• Fix hybrid functionals with pure Gaussian functionals
• Fix bug in memory estimation for GW calculations
• Stop hybrid functional calculations when band structure segment is request in a direction where the SCF k-grid has less than 3 k-points

Changes since release version 221103_1

DFPT refactorization

Connor Box

• DFPT, DFPT_reduce_memory, DFPT_polarisability, DFPT_dielectric, DFPT_phonon, DFPT_phonon_reduce_memory now use a common DFPT module, currently activated by setting DFPT_centralised .true. in the control.in
• Electronic friction calculations now support DFPT, for both clusters and periodics systems.
• Refactor of electronic friction driver, including improved scaling and output of electron-phonon coupling matrix elements using ELSI.
• DFPT centralised interface is interfaced to LibXC and supports LDA, GGA, and hybrid functionals
• Framework set to switch DFPT_centralised .true. as the default in the new-future.

DeltaSCF refactoring

Sam Hall and Dylan Morgan

• Refactored force_occupation_basis and force_occupation_projector keywords, re-written in an extensible format as a platform for future development
• Introduced new deltascf_projector and deltascf_basis keywords
• Significantly improved the scaling performance by using ELSI to calculate the non-Aufbau occupations and chemical potential
• Further improved the scaling by utilising other optimised matrix routines from ScaLAPACK and adding support for KS_method parallel in aperiodic systems
• See https://www.archer2.ac.uk/ecse/reports/eCSE04-03/ for further details

Ab initio simulations of tip-enhanced Raman spectroscopy

Yair Litman, Alaa Akkoush

• Allows ab initio simulations of polarizability tensors including a numerical inhomogeneous local hartree potential originally calculated by TDDFT responses from metallic tip-like structures
• Repository with a how-to example, input files including the local hartree potentials for selected geometries, and a script to create tip-enhanced Raman images with this implementation in FHI-aims can be found in https://github.com/sabia-group/TERS_Tutorial

Minimal + s basis implementation

Elisabeth Keller

• minimal+s basis set: cost-efficient, near-minimal basis set with correction for basis set incompleteness error (currently parametrized for PBE).
• Purpose: overcomes runtime limitations and memory issues for fast (pre-)relaxation, MD, large-scale geometry optimizations.
• Where to find: species_defaults/defaults_2020/minimal+s/
• Usage: Copy-paste the minimal+s species files into control.in. The corrections are automatically invoked by using the minimal+s species files.

GreenX Library

Francisco Delesma

• Green-X is a collection of libraries for low-scaling RPA and GW methods.
• We use minimax grids implemented in GreenX for canonical RPA, RPA gradients, and GW calculations.
• The minimax grids are available for periodic and non-periodic computations.

Optimization of periodic GW

Florian Merz, Min-Ye Zhang

• Reduced time consumption for self-energy by limiting QPE calculation to energy states near Fermi level.
• Reduced memory consumption for reciprocal lvl triples, along with detailed memory report in run and a final report.
• Bug fixes for occasional hanging.

MultiPole Expansion (MPE) implicit solvent model for periodic systems

Pavel Stishenko, Jakob Filser

• The new MPE solvent model (keyword mpe-ncps) uses Piecewise Solvent region representation. It increases sparsity of the MPE matrix, improves memory efficiency, and has a potential for calculations speed-up.
• The MPE model with Piecewise Solvent can be used for systems with periodic boundary conditions.

Atomic Simulations Interface (ASI) API

Pavel Stishenko

• Atomic Simulations Interface (ASI) is a C-style API. It is available if FHI-aims is build as a library. The Python wrapper asi4py is available in PIP.
• ASI API supports setting atomic coordinates, lattice size, custom electrostatic potential, and density matrix.
• ASI API supports getting total energy, atomic forces, charges, stress, electrostatic potential, and density, overlap and hamiltonian matrices.

ELSI interface for spin-orbit coupling

Uthpala Herath

• Implement static excitations method for studying electron excitations.
• Replace get_occupation_numbers_p0 with ELSI’s elsi_compute_mu_and_occ subroutine for SOC calculations.
• Increase number of empty states for SOC calculations to converge the SOC results.
• Replace subroutine check_norm with ELSI’s check_electrons.

Further improvements of RPA Forces

Muhammad Tahir

• RPA+rSE forces for molecules
• RPA force for solids, stress is conserved
• Added evaluation of direct particle-hole RPA total energy (plasmon approach)
• Added direct phRPA+ SOSEX total energy (not dependent on frequency integration grid)
• direct-ring-ccsd from direct-particle-hole RPA total energy
• Added evaluation of analytical gradient of long-range coulomb interaction (needed for RPA force for solids under have_Ewald tag)

Further developments

• Added routines for localising molecular orbitals via optimised unitary transformations; includes localised molecular orbital visualisation and restarts (Gabriel Bramley)
• Implementation of GPU-offloading in the RI-V routines on Nvidia GPUs (CUDA) (Moritz Leucke, Roman Kempt, Antonio Delesma, Ramon L. Panades-Barrueta)
• Refinement of the Hybrid functionals auto-tuning parameters: Auto-tuning parameters are chosen more conservative to avoid out-of-memory crashes (Florian Merz)
• Written new slab identification routines (Osama Jalil)
• Adapting default choices for preconditioner: only switch on the preconditioner when a slab s identified. The preconditioner will be switched off for bulk materials by default now. Please report back, if that affects your SCF convergence significantly.
• Fixing rotational invariance issue of the on-site nuclear Hartree potential (Volker Blum, Uthpala Herath)
• Added basis sets for Periodic GW calculations that include for_aux functions (Uthpala Herath)
• Updated the default relativistic setting to atomic_zora scalar (Konstantin Lion)
• Updated CI to use Docker image with Ubuntu20, Intel 2022, MPICH 3.3.2 and GNU10.5 (Uthpala Herath)
• update of LibXC to version 6.1.0 (Osama Jalil)

News from the FHI-aims ecosystem

Graphical Interface for materials simulations: GIMS

Andrey Sobolev

• New workflows for GW calculations and MD simulations
• Visualize Hirshfeld and Mulliken charges.
• Improved handling of the band structure visualization
• Where to find: gims.ms1p.org

New tutorials

• Embedded-Cluster Modelling With FHI-aims (Oscar van Vuren)
• MDAnalysis and FHI-aims (Oliver Beckstein)
• An overview of all tutorials can be found here