The **Lumen** code is derived from Yambo 4.1.3. Lumen implements a new approach to study non-linear response in solids and nanostructures. Notice that all the non-linear implementation of Lumen will be soon included in the official Yambo distribution, so if you are not in hurry to use it, just wait for the new version of Yambo.

**Differences from Yambo**

- Since non-linear response requires double-precision to work, by default Lumen is compiled in double precision. In order to compile Lumen in single-precision use the flags --enable-sp.
- Old Yambo databases are not compatible with Lumen. In general please do not mix databases of Yambo and Lumen.
- Libxc and IotK and NetCdf libraries are already included in Lumen package.

**Download the code**

- lumen-1.3.tgz [02/10/2018]
- lumen-1.2.tgz [16/01/2017]
- lumen-1.1.tgz [22/11/2017]
- lumen-1.0.tgz [06/11/2017]

The last version of Lumen code can be downloaded from git-hub at the address:

https://github.com/attacc/lumen

Since **Lumen** is derived from Yambo, if you use it please cite the Yambo paper:

*Yambo: an ab initio tool for excited state calculations.*

A. Marini, C. Hogan, M. Grüning, and D. Varsano, Comp Phys Comm., **180**(8), 1392(2009)

If you use Lumen for **non-linear optics spectroscopy** please cite:

*Nonlinear optics from an ab initio approach by means of the dynamical Berry phase: Application to second-and third-harmonic generation in semiconductors*

C. Attaccalite, M. Grüning, Physical Review B **88** (23), 235113(2013)

If you use **Time-Dependent Polarization Theory** implemented in Lumen please cite:

*Dielectrics in a time-dependent electric field: a real-time approach based on density-polarization functional theory*

M. Grüning, D. Sangalli, C. Attaccalite, Physical Review B **94** (3), 035149(2016)

If you use **Real-Time Bethe-Salpeter equation** please cite:

*Real-time approach to the optical properties of solids and nanostructures: Time-dependent Bethe-Salpeter equation.*

C. Attaccalite, M. Grüning, A. Marini, Physical Review B, **84**(24), 245110 (2011)

- Second-Harmonic Generation in Two-Dimensional Materials

Myrta Grüning

Encyclopedia of Modern Optics 2nd edition, Elsevier (2018) - Two-photon absorption in two-dimensional materials: The case of hexagonal boron nitride

Claudio Attaccalite, Myrta Grüning, Hakim Amara, Sylvain Latil, François Ducastelle

arXiv preprint: 1803.10959 - Two-photon absorption spectrum of liquid water and the effect of nondiagonal self-energy elements in the self-consistent GW approach on the band gap

Vafa Ziaei and Thomas Bredow

Physical Review B**96**, 245109 (2017) -
Optical properties of periodic systems within the current-current response framework: Pitfalls and remedies

Davide Sangalli, J. A. Berger, Claudio Attaccalite, Myrta Grüning, and Pina Romaniello

Phys. Rev. B**95**, 155203 (2017) - Excitonic effects in third harmonic generation: the case of carbon nanotubes and nanoribbons

C. Attaccalite, E. Cannuccia, M Grüning

Phys. Rev. B**95**, 125403 (2017) - Non-linear response in extended systems: a real-time approach

C. Attaccalite

arXiv preprint arXiv:1609.09639 - Dielectrics in a time-dependent electric field: a real-time approach based on density-polarization functional theory

M Grüning, D Sangalli, C Attaccalite

Physical Review B**94**(3), 035149(2016) - Performance of polarization functionals for linear and nonlinear optical properties of bulk zinc chalcogenides ZnX (X= S, Se, and Te)

M. Grüning, C. Attaccalite

Physical Chemistry Chemical Physics**18**(31), 21179-21189(2016) - Strong second harmonic generation in SiC, ZnO, GaN two-dimensional hexagonal crystals from first-principles many-body calculations

C. Attaccalite, A. Nguer, E. Cannuccia, M Grüning

Physical Chemistry Chemical Physics**17**(14), 9533-9540(2015) - Second harmonic generation in h-BN and MoS
_{2}monolayers: Role of electron-hole interaction

M. Grüning, C. Attaccalite

Physical Review B**89**(8), 081102(2014) - Nonlinear optics from an ab initio approach by means of the dynamical Berry phase: Application to second-and third-harmonic generation in semiconductors

C Attaccalite, M Grüning

Physical Review B**88**(23), 235113(2013)