# 1.1.3. New features and updates¶

Below is presented a list of the major new features of Molcas. These features comprise a number of new codes and introduction of new methods, but also considerable updates of many of the programs in Molcas. We keep some history, so that people who are using older versions of Molcas can get a feeling for what has happened on later versions

New features in 8.0:

• General improvements:
• includes major bug fixes;
• enhanced performance;
• better parallelization;
• better support for the Intel, and GCC compilers;
• New codes and major updates:
• Stochastic-CASSCF allows to choose large active spaces (currently active spaces containing up to 50 electrons and 50 orbitals have been tested) in part circumventing the exponential scaling limitation of the standard CASSCF method;
• MC-PDFT combines multiconfigurational wavefunctions with density functional theory to recover both static and dynamical correlation energy;
• GASSCF allows for more flexibility in choosing the active space;
• EMBQ is general purpose embedding technique;
• FALCON is fragment-based approach for computing an electronic energy of the large systems;
• GEO/HYPER module for constrained multi-fragment geometry optimisation in internal coordinates;
• enhanced I/O via the Files In Memory technology;
• CRYS: extraction of the parameters of the multiplet-specific crystal field for lanthanides;
• UBAR: construction of the blocking barriers of single-molecule magnets;
• ABCC: magnetic and anisotropy axes are given in the crystallographic $$abc$$ system;
• New features in existing codes:
• Relativistic exact decoupling (X2C/BSS/infinite-order DKH);
• Local X2C/BSS/infinite-order DKH;
• RICD analytical gradients are available for the MBPT2, and CASSCF methods;
• auto-segmentation in CD-based coupled cluster CHCC and CHT3 modules;
• Orbital-free density embedding;
• more robust and efficient SLAPAF module;
• enhanced EMIL functional;
• Installation and tools:
• first release of the Global Arrays free MOLCAS; a new parallel framework of MOLCAS requires only MPI-2 library;
• better support for Mac OS X (including the both serial and parallel installations);