目录：https://www.atomicorp.com/channels/atomic/centos/6/x86_64/RPMS/

首先：

wget -q -O - http://www.atomicorp.com/installers/atomic.sh | sh

会在yum的配置目录中增加一个新的yum源配置文件：/etc/yum.repos.d/atomic.repo

安装php等软件时会报错：

warning: rpmts_HdrFromFdno: Header V3 RSA/SHA1 Signature, key ID 4520afa9: NOKEY
Retrieving key from file:///etc/pki/rpm-gpg/RPM-GPG-KEY.art.txt

The GPG keys listed for the “CentOS / Red Hat Enterprise Linux 6 – atomicrocketturtle.com” repository are already installed but they are not correct for this package.
Check that the correct key URLs are configured for this repository.

解决方法：

yum update atomic-release

升级下可以解决。