In this page you will find out more about YAMBO and its capabilities.

[00] Introduction

[01] Features

[01.01] Quasiparticle properties

[01.02] Spectroscopic properties

[01.03] Postprocessing

[02] Technical Details

[02.01] Methods and compatibility

[02.02] Platforms and parallel computing

[03] Reference publications

[03.01] Main YAMBO papers

[03.02] Papers describing YAMBO implementations

[00] Introduction

YAMBO is a plane-waves first-principles code for calculating excited-state properties – such as quasiparticle energies and optical spectra – of solid-state systems within the framework of many-body perturbation theory (MBPT) and time-dependent density functional theory (TDDFT).

Quasiparticle energies are calculated within the GW approximation for the self-energy. Optical properties are evaluated either by solving the Bethe–Salpeter equation (BSE) or by using the adiabatic local density approximation (ALDA).

YAMBO calculations require a previously computed electronic structure and for this reason it is currently interfaced with Quantum ESPRESSO and ABINIT.

Aiida plugins for YAMBO, such as YamboCalculation and YamboConvergence, automatise the very complex multi-parameter dependence that characterises GW calculations. 

[01] Features

What can YAMBO do?

[01.01] Quasiparticle properties

  • GW calculations of electronic excitation
  • Dynamical screening (plasmon-pole, multi-pole approximations or full-frequency)
  • Finite temperature electronic energies and lifetimes
  • Electron-phonon corrections

[01.02] Spectroscopic properties

Eur. Phys. J. B 91, 286 (2018)
  • Optical absorption and excitons
  • Electron Energy Loss
  • Kerr rotation
  • Real-Time dynamics: Time–dependent Screened Exchange
  • Nonlinear optical properties (including Berry’s phase polarization)

[01.03] Postprocessing

  • Interpolation of quasiparticle and exciton energies and double grids
  • Representation of excitonic wave functions in real and reciprocal space
  • Python data analysis and scripting tool including:
    • Quality-of-life automated scripts
    • Visualization and plotting options for most quantities
    • Data analysis tools for encoded databases beyond standard outputs
arXiv:2204.11105

[02] Technical details

[02.01] Methods and compatibility

YAMBO supports norm-conserving pseudopotentials and many exchange-correlation functionals, from LDA to generalized-gradient corrections (PW91, PBE, B88-P86, BLYP) to meta-GGA, exact exchange (HF) and hybrid functionals (PBE0, B3LYP) via the libxc library.

Noncollinear magnetism and spin-orbit coupling calculations are also supported. There are several available Coulomb interaction cutoff geometries, sum-over-states terminators and interpolation schemes.

YAMBO is a Fortran/C code that exploits a number of optimized libraries such as BLAS, LAPACK, FFTW, SCALAPACK, NetCDF/HDF5, PETSC, and SLEPC.

J. Phys.: Condens. Matter 31 325902

[02.02] Platforms and parallel computing

The code is parallelized over several MPI+OpenMP levels. YAMBO stores information in several database files (the biggest reaching few GBs in size for our systems) for which a NetCDF/HDF5 format is adopted, optimizing IO and data portability. The code has been extensively tested and used on different HPC architectures, for large scale systems.

The YAMBO implementation of GW is parallel on the k/q grids, bands summation and quasiparticle energies, using a hybrid MPI-OpenMP approach. Explicit OpenMP support is implemented following different strategies according to the specific kernels. The BSE routines are parallel on k-points, electron-hole basis elements, and transitions. GW and BSE calculations are computationally expensive and, for complex materials and surfaces, can be performed only exploiting the resources offered by modern Tier0 systems.

The GPU porting was first made using CUDA-Fortran, and more recently enlarged to other programming models (like OpenACC and OpenMP5, both in development). We make an intense use of pre-processor macros that activate the language chosen at compile time, allowing YAMBO to optimally integrate MPI-OpenMP with programming models for GPGPU. 

[03] Reference publications

[03.01] Main YAMBO papers

• Many-body perturbation theory calculations using the yambo code
D. Sangalli, A. Ferretti, H. Miranda, C. Attaccalite, I. Marri, E. Cannuccia, P.M. Melo, M. Marsili, F. Paleari, A. Marrazzo, G. Prandini, P. Bonfa’, M. O. Atambo, F. Affinito, M. Palummo, A. Molina Sanchez, C. Hogan, M. Grüning, D. Varsano and A. Marini
Journal of Physics: Condensed Matter 31 325902 (2019)

• yambo: An ab initio tool for excited state calculations
A.  Marini, C. Hogan, M. Grüning, and D. Varsano
Computer Physics Communications 180, 1392 (2009)

[03.02] Papers describing the YAMBO implementations