WP1: Study of the CSA building-blocks in molecular form and gas phase. Pointing out the special properties/weird/exotic effects

  • (A1.1) Structural relaxation and analysis of the electronic structure (HOMO-LUMO gap, shape of the orbitals, bond-order analysis, Bader charges) in reduced/oxidized states. The scope is to fine-tune the computational setup and to compare the results with different basis sets, exchange correlation functional etc; we use experimental data to compare with theoretical ones; focus will be on the redox potentials as well as spectroscopy (IR and UV) provided by the UCL group.O basis quality by using the methodology based on Simplex algorithm described in [26]. The quality of the basis sets is critical for the accuracy of the QMC, which justify the amount of time dedicated to this activity.

  • (A1.2) Analysis of the special cases: largest/smallest gaps, differences in Bader charges or redox potentials. Pointing out the most stable/unstable molecules according to their bond-order for selected atom pairs

WP2: The role of solvent effects upon the properties calculated at WP1

  • (A2.1) Calculation of geometric structures in presence of solvents for all CSAs. Solvents to me used: water, DMC, DMSO, EC

  • (A2.2) Analysis of the special cases in presence of solvents (see T2.1); role of solvent upon properties studied at WP1: largest/smallest gaps, differences in Bader charges and redox potentials. Pointing out the most stable/unstable molecules according to their bond-orders in selected bonds.

WP3: Structural properties of CSA-MOFs as periodic structures

  • (A3.1) Determination of the crystal structures of the available MOFs, to be delivered by the UCLLouvain la Neuve (see the cooperation agreement attached to this application) using X-Ray diffraction. In the obtained samples will be searched small single crystals; then the crystal structure will be determined using the SuperNova single crystal diffractometer with two microsources (Mo and Cu). From crystal structure solution, the simulated powder diffraction pattern will be compared with the experimental one to see if the analyzed crystals are representative for the powder samples and the samples have the desired purity to allow further characterization. If in the synthesized samples it will not find single crystal for X-ray diffraction then the samples they will be recrystallized by high throughput screening using small-scale crystallization platform (Crissy XL). If no single crystals are to be obtained and only powder data are available, the structural models will be obtained by searching in direct space using Simulated annealing and Parallel Tempering methods followed by refining model structure by the Rietveld method.

  • (A3.2) Theoretical determination of the structures by using SIESTA code and periodic boundary conditions in order to establish the best computational setup. We’ll use in the first approach van der Waals exchange-correlation functional [31]; in the second approach, we’ll use the solidadapted exchange correlation functional PBEsol [32] and Grimme corrections [33].

  • (A3.3) Prediction on the structures not available but with similar structures, based on DFT calculations on MOFs. Examples here include replacing the ligand metallic atoms with other metals in the list and/or adding structural groups to the central backbone in the CSA unit. The guess-structures will be the CSA-MOF; by using the computational setup validated in T3.2 we’ll optimize the crystal structure and geometric positions for new, potentially interesting compounds, as indicated by our results in WP1 and 2.

WP4: Study of electronic structure of the CSA-MOFs

  • (A4.1) Calculation of the band structures and density of states with/without Li atoms in MOF structure (i.e. reduced/oxidized states). This can be realized at various levels of accuracy (according to interest and available computing times) using SIESTA which provides flexibility on the accuracy/computing parameters. Role of the exotic/special situations detected among the isolated molecules: do the properties occurs in the bulk or not.

  • (A4.2) Bond orders and Bader charges calculations for MOFs with/without Li. The bond-orders will be computed by using the integral over the COOP curves which provides information on bond-order [29] and can be directly produced using SIESTA. Bader charges will be computed by using the electronic density stored in cube format.

  • (A4.3) A model for the conduction will be produced, by adapting the tight-binding methodologies. Also, we foresee a second version based on nearly free electrons. The data will be fitted to the existing ab-initio band structures, density of states and Bader charges.

WP5: Development of a code for the analysis of thermodynamic properties in periodic structures

  • (A5.1) Writing the Fortran 90 code (reading the structural data – Fourier transform the speed –produce the VDOS – using the Bose-Einstein distribution to compute the thermodynamic potentials: entropy and the free energy).

  • (A5.2) Testing the code on simple molecule (e.g. benzene, quinone, DMSO); the thermodynamic data to be compared to results for the same molecular systems (data produced using GAMESS).

WP6: Analyzing the thermodynamic stability of the CSA-MOF

  • (A6.1) Performing ab-initio Verlet/microcanonical molecular dynamics for the periodic structures investigated at WP4 with/without Li inserted in MOF structures.

  • (A6.2) Computing the temperature-dependent free energy and entropy from speeds produced in the Verlet dynamics; to be done for all systems with/without Li in the structures.

  • (A6.3) Comparison between our data and existing experimental results; stability of the molecules after cyclic voltametry will be evaluated by the values of the thermodynamic potentials in MOFs with/without Li inserted in structures. Summary of the results will be used to propose a qualitative model capable to establish rules for the most stable CSA-MOF under cyclic voltammetry (i.e. sequences of intercalation / elimination of Li atoms in the MOFs).

WP7: Management of the project and dissemination

  • (A7.1) Meetings with all member for reciprocal information/discussions.

  • (A7.2) Writing periodical reports on the project’s evolution and proposing methods for the optimization of activities (see the risk table below).

  • (A7.3) Writing papers, abstracts for conferences and other elements for dissemination of the results.