installing lammps on ubuntu

hi
when i type sudo apt-get update in terminal
i see this
Hit:1 http://archive.ubuntu.com/ubuntu artful InRelease
Ign:2 http://ppa.launchpad.net/gladky-anton/lammps/ubuntu artful InRelease
Err:3 http://ppa.launchpad.net/gladky-anton/lammps/ubuntu artful Release
404 Not Found
Reading package lists… Done
E: The repository ‘http://ppa.launchpad.net/gladky-anton/lammps/ubuntu artful Release’ does not have a Release file.
N: Updating from such a repository can’t be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

how it can be solved

please help me

tnks

hi
when i type sudo apt-get update in terminal
i see this
Hit:1 Index of /ubuntu artful
InRelease
Ign:2 Index of /gladky-anton/lammps/ubuntu artful
InRelease
Err:3 Index of /gladky-anton/lammps/ubuntu artful Release
  404 Not Found
Reading package lists... Done
E: The repository 'Index of /gladky-anton/lammps/ubuntu
artful Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is
therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user
configuration details.

how it can be solved

​this isn't really a LAMMPS problem, but an issue on ubuntu or rather the
PPA maintainer.​
thus if you want to have a matching pre-compiled LAMMPS package on ubuntu,
you have to discuss with the package maintainer.
otherwise, you can always download a source package of LAMMPS from
lammps.sandia.gov and compile it yourself following the instructions in the
LAMMPS manual.

axel.