###Time Dependent Density Functional Perturbation Theory (TDDFPT)

TDDFPT developers would be grateful if any scientific work done with TDDFPT
contained a reference to one of the following reference papers:

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Absorption spectroscopy:

turboTDDFT – A code for the simulation of molecular spectra using the Liouville–Lanczos approach 
to time-dependent density-functional perturbation theory  Original Research Article
Authors: Osman Baris Malcioglu, Ralph Gebauer, Dario Rocca, Stefano Baroni
Source: Computer Physics Communications   Volume: 182  Article Number: 1744  Published: APR 2011 

turboTDDFT 2.0 - Hybrid functionals and new algorithms within time-dependent 
density-functional perturbation theory
Authors: X. Ge, S. J. Binnie, D. Rocca, R. Gebauer, and S. Baroni
Source: Computer Physics Communications  Volume: 185  Article Number: 2080  Published: MAR 2014

Turbo charging time-dependent density-functional theory with Lanczos chains
Authors: D. Rocca, R. Gebauer, Y. Saad, and S. Baroni
Source: JOURNAL OF CHEMICAL PHYSICS   Volume: 128   Article Number: 154105   Published: APR 2008

Ultrasoft pseudopotentials in time-dependent density-functional theory
Authors: B. Walker, and R. Gebauer
Source: JOURNAL OF CHEMICAL PHYSICS   Volume: 127   Article Number: 164106   Published: OCT 2007

Efficient approach to time-dependent density-functional perturbation theory for optical spectroscopy
Authors: B. Walker, A. M. Saitta, R. Gebauer, and S. Baroni
Source: PHYSICAL REVIEW LETTERS   Volume: 96   Article Number: 113001   Published: MAR 2006

Book: Fundamentals of Time-Dependent Density Functional Theory,
M.A.L. Marques, N.T. Maitra, F.M.S. Nogueira, E.K.U. Gross, and A. Rubio,
Lecture Notes in Physics, Springer-Verlag, Berlin Heidelbnerg, volume 837, 2012.
Chapter 19: The Liouville-Lanczos Approach to Time-Dependent Density-Functional (Perturbation) Theory,
Authors: S. Baroni and R. Gebauer

Self-consistent continuum solvation for optical absorption of complex molecular systems in solution
Authors: I. Timrov, O. Andreussi, A. Biancardi, N. Marzari, and S. Baroni
Source: JOURNAL OF CHEMICAL PHYSICS   Volume: 142  Article Number: 034111 Published: JAN 2015

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Electron energy loss spectroscopy (EELS):

Electron energy loss and inelastic x-ray scattering cross sections from 
time-dependent density-functional perturbation theory
Authors: I. Timrov, N. Vast, R. Gebauer, and S. Baroni
Source: PHYSICAL REVIEW B   Volume: 88   Article Number: 064301   Published: AUG 2 2013
See also: PHYSICAL REVIEW B 91, 139901(E) (2015)

turboEELS - A code for the simulation of the electron energy loss and inelastic X-ray scattering spectra 
using the Liouville-Lanczos approach to time-dependent density-functional perturbation theory
Authors: I. Timrov, N. Vast, R. Gebauer, and S. Baroni
Source: Computer Physics Communications  Volume: 196  Article Number: 460 Published: 4 JUNE 2015

Ab initio study of electron energy loss spectra of bulk bismuth up to 100 eV
Authors: I. Timrov, M. Markov, T. Gorni, M. Raynaud, O. Motornyi, R. Gebauer, S. Baroni, and N. Vast
Source: PHYSICAL REVIEW B 95, 094301 (2017)

Electron energy loss spectroscopy of bulk gold with ultrasoft pseudopotentials and the Liouville-Lanczos method
Authors: O. Motornyi, N. Vast, I. Timrov, O. Baseggio, S. Baroni, and A. Dal Corso
Source: PHYSICAL REVIEW B 102, 035156 (2020)

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This module uses subroutines from PW, Modules and LR_Modules along with 
the general infrasturcture provided by Quantum ESPRESSO. 

The directory TDDFPT must reside immediately under the espresso directory for Makefiles to work. 

Standart compilation: Run "make tddfpt" in espresso directory where TDDFPT is a subdirectory
 
Directory Structure: 
bin      : The TDDFPT related binaries
src      : The source files
Doc      : The manual
Examples : Examples and tests. Each example has its own seperate Makefile. 
           Refer to the README under this subdirectory for further information. 
tools    : Various tools:
           1) The postprocessing code for calculating absorption spectrum and EELS.
           2) A script to recover reduced liouvillian in a format comprehensible to postprocessing
              code from the stdout. 
