Para openSUSE Factory execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:tiwai/openSUSE_Factory/home:tiwai.repo
zypper refresh
zypper install rxvt-unicode
Para 16.0 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:tiwai/16.0/home:tiwai.repo
zypper refresh
zypper install rxvt-unicode
Para 15.6 execute o seguinte como root:
zypper addrepo https://download.opensuse.org/repositories/home:tiwai/15.6/home:tiwai.repo
zypper refresh
zypper install rxvt-unicode