When simulating optical spectra with the Quantistry Lab, two curves are displayed as a result:  

• The real curve, which describes the dielectric polarization of the material  

• The imaginary curve, which describes the optical absorption  

Depending on the question, the curves provide the corresponding answers. Different calculation methods can be used for the simulations:  

• RPA (Random-phase approximation)  

• GW-BSE (G = Green's function, W = Screened Coulomb potential, BSE = Bethe-Salpeter equation)  

The RPA method is fast, low in price and provides basic information. The GW-BSE method takes more time, is more cost intensive, but provides extremely precise results.  

Typically, extensive expertise is required to use both, but in particular the GW-BSE method. With Quantistry Lab, it's easy because the simulations are automated.  

This is especially clear with the Workflow Designer. Here you specify the material and select the method "Optical Response". Done.  

What you see at first glance in the simulation result: The dashed line, which marks the band gap. This makes the minimal energy immediately recognizable that must be expended for electronic excitations in the material.

Finally, there is a convenience function for those who want to know exactly. The zoom function, with which you can view the curve in detail.  

With QuantistryLab, all you need to run chemical simulations is a web browser. Our cloud-native platform redefines R&D with a holistic computational approach, from quantum to AI. Our customized Use-Case Modules offer tailored solutions to overcome your specific R&D challenges. Get in touch and start simulating today.