<![CDATA[Abstrak Simulasi komputasi telah banyak digunakan untuk penelitian sifat fisis dan properti dari material dengan memodelkan sistem fisisnya ke dalam algoritma komputasi. Seperti yang dikerjakan pada penelitian ini, dalam mengkaji pengaruh Spin-Orbit Interactions (SOI) dan medan listrik eksternal terhadap struktur elektronik CoCl2 monolayer, dilakukan perhitungan berbasis Density Functional Theory (DFT) dengan fungsi energi pertukaran elektron Generalized Gradient Approximation (GGA) pada openMx. Hasilnya menunjukkan pada keadaan energi dasar, CoCl2 monolayer bersifat semikonduktor dengan celah pita langsung. Celah pita energi berkurang dalam pengaruh Spin-Orbit Interaction (SOI) di titik K. Selain itu, penambahan medan listrik eksternal menyebabkan terjadinya transisi sifat elektronik dari semikonduktor celah pita langsung ke celah pita tidak langsung dan kemudian menjadi logam. Penggabungan antara Spin-Orbit Interaction dengan medan listrik menyebabkan semakin cepatnya transisi sifat elektronik yang dialami CoCl2 monolayer. Kata Kunci. CoCl2 monolayer, struktur elektronik, spin-orbit interaction, Density Functional Theory Abstract Computational simulation has been widely used for research on physical properties and properties of materials by modeling the physical system into a computational algorithm. As done in this research, in studying the effect of Spin-Orbit Interactions and external electric field on the electronic structure of CoCl2 monolayer, Density Functional Theory based calculations were carried out with the Generalized Gradient Approximation (GGA) electron exchange energy function on openMx. The results show that in the ground energy state CoCl2 monolayer is a semiconductor with a direct band gap. The band gap energy is reduced under the influence of Spin-Orbit Interaction at K point. Furthermore, the addition of an external electric field causes the transition of electronic properties from direct band gap semiconductor to indirect band gap and then to metal. And by combining the Spin-Orbit Interaction with an external electric field, it can make the transition of electronic properties in CoCl2 monolayer become faster. Keywords: CoCl2 monolayer, electronic structure, spin-orbit interaction, Density Functional Theory]]>
