This research is currently supported by PASC, Platform for Advanced Scientific Computing and by MARVEL, a National Centre for Competence in Research

Releases

Environ-1.0  is the latest release of Environ. It is interfaced with

the Quantum-ESPRESSO package and compatible with

versions QE-6.1.X and QE-6.2.X. Compatibility with previous versions of 

Quantum-ESPRESSO is only guaranteed with Environ-0.2. 

From this release, Environ is also available as a public GitLab repository:

tag v1.0 corresponds to the version of the module compatible with QE-6.2.X. 


The new features of Environ-1.0 are the following:

          needed in dielectric embedding environments.

  • Extension to solve linearised (possibly size-modified) Poisson-Boltzmann problems, needed in modelling dilute electrolyte embedding environments.
  • Non-linear solvent-aware definition of the continuum interface, to avoid artefacts in the definition of the boundary in complex systems, such as unphysical pockets of continuum embedding environments that are smaller than the solvent molecular radius.
  • A full set of tests to check consistency of compilation and implementation.


The previous functionalities of Environ, available to all the supported distributions of Quantum-ESPRESSO, are the following:

  • Continuum dielectric solvation model, defined self-consistently on the electronic density of the system.
  • External pressure model, defined in terms of the quantum-volume of the system.
  • External surface tension model, defined in terms of the quantum-surface of the system.
  • Point-counter-charge correction schemes to remove periodic boundary conditions artefacts in isolated (0D) and slab (2D) systems.
  • Modifications of Martyna-Tuckermann PBCs correction schemes to account for the presence of a continuum dielectric embedding.
  • Fully tested and easier to use external fixed charge densities of arbitrary shape and dimensionality.
  • External user-defined dielectric regions of arbitrary shape and dimensionality, to simulate the effect of complex environment such as interfaces, substrates, nanoparticles, etc.
  • Restart, with the possibility to include environment effects from the initialisation step, providing a substantial speedup for geometry optimisation calculations.


The above functionalities are coupled with the following types of calculations:

  • Possibility to perform single point calculations, geometry optimizations, and Born-Oppenheimer molecular dynamics simulations, through the PW code of the Quantum-ESPRESSO package.
  • Possibility to perform transition state calculations via the nudged elastic band method, through the NEB code of the Quantum-ESPRESSO package.
  • Possibility to perform the calculation of optical spectra  via time-dependent density functional perturbation theory, through the TDDFpT code (only for the continuum dielectric contribution).
  • Only starting from QE-5.3.0, Environ-0.2 is coupled with the CP code of the Quantum-ESPRESSO  package, to perform Car-Parrinello and damped molecular dynamics simulations. 


All the above simulations are compatible with the main features of Quantum-ESPRESSO, namely pseudo-potentials-based plane-wave periodic-boundary-conditions simulations at the density functional theory level, with k-point integration. In particular the following features are all compatible with Environ (a more comprehensive list of the capabilities of Quantum-ESPRESSO can be found in the project documentation):

  • Norm-conserving, ultrasoft and projector-augmented wave (PAW) pseudopotentials.
  • Local density approximation (LDA) functionals, Generalized Gradient approximation (GGA) functionals, hybrid functionals,  van der Waals (vdW) nonlocal density functionals.
  • Hubbard U.


The features which are still not available and are under development are:

  • User-friendly installation procedure: the set up of the module inside the released Quantum-ESPRESSO package is still not user-friendly and requires to follow a rather simple, but long, procedure.
  • Coupling with the GIPAW code of the Quantum-ESPRESSO package, to calculate magnetic resonance spectra.