This study continues the author’s previous papers where a refined description of the chief factors of a parabolic maximal subgroup involved in its unipotent radical was obtained for all (normal and twisted) finite simple groups of Lie type except for the groups \({}^{2}F_{4}(2^{2n+1})\) and \(B_{l}(2^{n})\). In present paper, such a description is given for the group \({}^{2}F_{4}(2^{2n+1})\). We prove a theorem in which, for every parabolic maximal subgroup of \({}^{2}F_{4}(2^{2n+1})\), a fragment of the chief series involved in the unipotent radical of this subgroup is given. Generators of the corresponding chief factors are presented in a table.

本研究继续作者之前的论文，其中除了群\({}^{ 2}F_{4}(2^{2n+1})\)和\(B_{l}(2^{n})\)。在本文中，对群\({}^{2}F_{4}(2^{2n+1})\)给出了这样的描述 。我们证明了一个定理，其中，对于\({}^{2}F_{4}(2^{2n+1})\) 的每个抛物线极大子群 ，有一个主级数的片段，该片段包含在这个单能根中给出了子群。表中列出了相应主要因素的生成器。