Nuclear quantum effects slow down the energy transfer in biological light-harvesting complexes

We assess how quantum-mechanical effects associated with high-frequency chromophore vibrations influence excitation energy transfer in biological light-harvesting complexes. After defining a classical nuclear limit that is consistent with the quantum-classical equilibrium, we include nuclear quantum effects through a variational polaron transformation of the high-frequency vibrational modes. This approach is validated by comparison with fully quantum-mechanical benchmark calculations and applied to three prototypical light-harvesting complexes. For light-harvesting complex 2 of purple bacteria, the inter-ring transfer is 1.5 times slower in the quantum treatment than the classical. For the Fenna-Matthews-Olson complex, the transfer rate is the same in both cases, whereas for light-harvesting complex II of spinach, transfer is 1.7 times slower in the quantum treatment. The effect is most pronounced for systems with large excitonic energy gaps and strong vibronic coupling to high-frequenc..., , , # Nuclear quantum effects slow down the energy transfer in biological light-harvesting complexes

[https://doi.org/10.5061/dryad.sj3tx96fn](https://doi.org/10.5061/dryad.sj3tx96fn)

## Description of the data and file structure

### Files and variables

#### File: results.zip

**Description:** 

Files starting with \"LH2\", \"FMO\" or \"LHC2\" contains the plotted data with time (in fs) as first column and populations (unitless) in the following columns.

Each file is named according to the pattern [system]-[population type or figure number]-[method].dat

* \[system]:
* LH2: 24-site light-harvesting complex 2 in purple bacteria
* FMO: 7-site Fenna-Matthews-Olson complex
* LHC2: 14-site light-harvesting couplex II in spinach
* \[population type or figure number]:
* B850: total population of sites 16-24
* sites: population of each site 1-24 in the columns following time
* Pa: total population of Chla sites
* fig2: population of each site 1-7 for the model used in Fig2
* figS1: ...,