The Modified Half-Normal Distribution R package mhn version 0.1.1 Provides density, distribution, quantile, and random generation functions for the Modified Half-Normal (MHN) distribution, along with moments and mode; the Fox-Wright Psi normalizing constant is evaluated internally. The MHN distribution arises as a conditional posterior in Bayesian Markov chain Monte Carlo and generalizes the half-normal, truncated normal, and square-root gamma distributions. Implements efficient sampling via the Sun, Kong & Pal (2023) <doi:10.1080/03610926.2021.1934700> algorithms and the Gao & Wang (2025) <doi:10.1080/03610918.2025.2524551> relaxed transformed density rejection method. Software Depends: R (>= 4.0.0) Imports: Rcpp (>= 1.0.7) LinkingTo: Rcpp, BH (>= 1.78.0-0) Suggests: testthat (>= 3.0.0), knitr, rmarkdown, bench, Rmpfr Tomotaka Momozaki <momozaki.stat@gmail.com> Comprehensive R Archive Network (CRAN) Tomotaka Momozaki [aut, cre] MIT + file LICENSE (https://CRAN.R-project.org/package=mhn/LICENSE) 2026-09-23 application/tgz https://CRAN.R-project.org/package=mhn doi:10.32614/CRAN.package.mhn