Wipe out running configuration in Cisco IOS-XR

For IOS, the equivalent command of “write erase” to IOS-XR is the command “commit replace”

RP/0/RSP0/CPU0:ASR9K(config)#commit replace ?
best-effort   Commit the configuration changes via best-effort operation
comment       Assign a comment to this commit
confirmed     Rollback this commit unless there is a confirming commit
force         Override the memory checks
label         Assign a label to this commit
save-running  Save running configuration to a file
show-error    Displays commit failures immediately
<cr>          Commit the configuration changes via pseudo-atomic operation

commit replace

RP/0/RSP0/CPU0:ASR9K(config)#commit replace 
Tue May 14 14:20:33.387 SGP

This commit will replace or remove the entire running configuration. This
operation can be service affecting.
Do you wish to proceed? [no]: yes

RP/0/RSP0/CPU0:ios(config)#