Lignin is a biopolymer with a heterogenous structure, that is one of the main components of wood. In the plant it is important for the stability and water transport seemingly adapting its structure to the specific need of different plant tissues. One of these adaptations can be seen in compression wood (CW), a type of reaction wood that stabilizes leaning stems or branches. In CW the chemical structure of lignin is different compared to normal wood (NW), as well as showing changes on the cell level. Studying and understanding the differences could help the forestry industry dealing with the nowadays seen as inferior wood as well as inspire the design of new materials. Another context is the delignification in kraft cooking aiming at obtaining wood pulp containing mainly cellulose. This is done by cooking wood chips with sodium hydroxide and sodium sulfite, removing lignin and other components from the chips. Understanding the properties of lignin segments will help improve the efficiency of the process in terms of energy and biomass. This project focusses on Molecular Dynamics (MD) simulations of lignin fragments, cellulose as well as lignin in interaction with cellulose. The studies will provide parameters and insights on an atomistic level focussing on either material or their interaction. Specific examples of the information that will be gained are radius of gyration of lignin segments, hydromechanics and diffraction related. The simulations are part of larger projects, where they are combined with larger size-scale simulations or experimental results. One example is a continuous model, that combines different size scales, providing multi-scale inside into processes occurring during delignification. The project focussing on the delignification in the kraft cooking is funded by Vinnova and is part of treesearch.