The difference between the atheists and the scientists is this: atheists can afford to be dogmatic or close-minded, but scientists cannot; their job or profession forbids them to be so. As scientists they have got some responsibility that the atheists do not have. As scientists they are supposed to provide explanation for all the events, phenomena or effects in nature and therefore they have to keep their mind open to the possibility that they may not always be able to explain everything purely naturally.
Scientist Victor J Stenger was an atheist, but like most of the atheists he was not close-minded. He did not completely rule out the possibility that there might be a God. In the year 2007 he published a book 'God: The Failed Hypothesis. How Science Shows That God Does Not exist'. In the introduction of that book he wrote the following:
"Indeed, the "God of the gaps" has long been a common argument for God. Science does not explain everything, so there is always room for other explanations and the believer is easily convinced that the explanation is God. however, the God of the gaps argument by itself fails, at least as a scientific argument, unless the phenomenon in question is not only currently scientifically inexplicable but can be shown to forever defy natural description. God can only show up by proving to be necessary, with science equally proven to be incapable of providing a plausible account of the phenomenon based on natural or material processes alone." (pp 13-14)1
So as per Stenger if there is one single phenomenon of nature for which science is proven to be incapable of providing a plausible account based on natural or material processes alone and which can be shown to forever defy natural description, then there, and there only, God can show up by proving to be necessary as an explanation.
Not only that. In the year 2009 British Scientist Edgar Andrews published a book 'Who Made God' in which he severely criticised the book "God: the Failed hypothesis" by Stenger (Chapter 5). In reply Stenger wrote the following:
"Anyone who has read any of my books knows I would never say that models detect anything. I simply say that God is not needed as part of any existing models but make clear that, if the evidence should require it, science should be required to include supernatural causes. If anything, Andrews should appreciate that, unlike most scientists, I allow for the possibility that we may not always be able to explain everything purely naturally. Currently we can, but I cannot predict the future."2
Here also we can see that he is not completely ruling out the possibility for the existence of the supernatural. This possibility can only be completely ruled out if, and only if, science can provide a natural explanation for each and every phenomenon of nature without any single exception.
There is one more scientist who like Victor J Stenger keeps his mind open to the possibility that as scientists one day they may also have the need of God as an explanation for some phenomenon of nature. Sean M Carroll is a theoretical physicist; to the outer world he is known to be an atheist. But despite that in November 1, 2010 he wrote an article (Is Dark Matter Supernatural?) that clearly shows his open-mindedness regarding this. Here is a relevant quote from that article:
“There is a perfectly good question of whether science could ever conclude that the best explanation was one that involved fundamentally lawless behavior. The data in favor of such a conclusion would have to be extremely compelling… but I don’t see why it couldn’t happen. Science is very pragmatic, as the origin of quantum mechanics vividly demonstrates. Over the course of a couple decades, physicists (as a community) were willing to give up on extremely cherished ideas of the clockwork predictability inherent in the Newtonian universe, and agree on the probabilistic nature of quantum mechanics. That’s what fit the data. Similarly, if the best explanation scientists could come up with for some set of observations necessarily involved a lawless supernatural component, that’s what they would do. There would inevitably be some latter-day curmudgeonly Einstein figure who refused to believe that God ignored the rules of his own game of dice, but the debate would hinge on what provided the best explanation, not a priori claims about what is and is not science.”3
From above we can see that the question as to whether there is any supernatural or not is purely a practical one. If scientists fail to provide a suitable explanation for certain phenomenon of nature by every natural means, then they are ready to go for the supernatural. Atheists do not have to face such crisis in their life, so they can very easily be close-minded.